Add new i18n languages and update existent ones

- Add 21 new languages where the UI was translated (all translations
  are 100% complete except for Chinese Simplified (96%)
  and Amharic (37%)).
- Update some translations for preexistent languages.

Change-Id: I64be0a2dd551c12af1547a616b4f49f97c471bde
diff --git a/src/_locales/et/messages.json b/src/_locales/et/messages.json
new file mode 100644
index 0000000..63f59f8
--- /dev/null
+++ b/src/_locales/et/messages.json
@@ -0,0 +1,114 @@
+{
+	"appName": {
+		"message": "Tõlgi valitud tekst",
+		"description": "The app name"
+	},
+	"appBetaName": {
+		"message": "Tõlgi valitud tekst (Beta)",
+		"description": "The beta app name"
+	},
+	"appDescription": {
+		"message": "Tõlgi valitud tekst Google'i tõlkega",
+		"description": "The app description"
+	},
+	"contextmenu_title": {
+		"message": "Tõlgi valitud tekst...",
+		"description": "Title of the context menu that appears when a right click is done. Inside this parent menu there are the menus"
+	},
+	"contextmenu_title2": {
+		"message": "Tõlgi valitud '$language$' keelde",
+		"description": "Title of the context menu that appears when a right click is done and there's only one language available.",
+		"placeholders": {
+			"language": {
+				"content": "$1",
+				"example": "Language to translate into."
+			}
+		}
+	},
+	"contextmenu_edit": {
+		"message": "Muuda keeli...",
+		"description": "Title of the option inside the 'Translate section into...' context menu."
+	},
+	"options_welcome": {
+		"message": "Tere tulemast!",
+		"description": "Title of the options page"
+	},
+	"options_introduction": {
+		"message": "Palun valige keeled mida soovite, et kuvaksime \"tõlkimise\" menüüs.",
+		"description": "Introduction paragraph to the options pages"
+	},
+	"options_languageselectheader": {
+		"message": "Keeled:",
+		"description": "Header of the language select option."
+	},
+	"options_otheroptionsheader": {
+		"message": "Teised valikud:",
+		"description": "Header of the options page."
+	},
+	"options_tabsoption_1": {
+		"message": "Ava Google'i tõlge iga tõlke kohta uues vahelehes.",
+		"description": "Option which defines how should the app behave in relation to tabs."
+	},
+	"options_tabsoption_2": {
+		"message": "Ava Google'i tõlge uues vahelehes ja kirjuta viimase tõlkega see iga kord üle - avamata uusi vahelehti.",
+		"description": "Option which defines how should the app behave in relation to tabs."
+	},
+	"options_tabsoption_3": {
+		"message": "Ava Google'i tõlge paneelis (selleks tuleb teil aktiveeirda <a href='chrome://flags/#enable-panels' id='panelsflag'>--enable-panels</a> flag). <sup style='color:red; font-weight: bold;'> EKSPERIMENTAALNE</sup>",
+		"description": "Option which defines how should the app behave in relation to tabs."
+	},
+	"options_savebutton": {
+		"message": "Salvesta",
+		"description": "Save button in the settings page"
+	},
+	"options_addlanguage": {
+		"message": "Lisa keel",
+		"description": "Title for the 'Add language' dialog"
+	},
+	"options_addlanguage_addbutton": {
+		"message": "Lisa",
+		"description": "Add button in the footer of the languages list"
+	},
+	"options_language_label": {
+		"message": "Keel:",
+		"description": "Label for the language selector in the 'Add language' dialog"
+	},
+	"options_credits": {
+		"message": "Krediidid",
+		"description": "Title for the credits link and dialog"
+	},
+	"options_credits_homepage": {
+		"message": "koduleht",
+		"description": "Homepage link for an item in the credits. NOTE: put in in lowercase letters"
+	},
+	"options_credits_by": {
+		"message": "autor",
+		"description": "Fragment of the author statement in an item of the credits. NOTE: put in in lowercase letters. EXAMPLE: '{{options_credits_by}} Adrià Vilanova Martínez'"
+	},
+	"options_ok": {
+		"message": "OK",
+		"description": "OK button in the dialogs"
+	},
+	"options_cancel": {
+		"message": "Loobu",
+		"description": "Cancel button in the dialogs"
+	},
+	"notification_install_title": {
+		"message": "Täname, et paigaldasite 'Tõlgi valitud tekst'"
+	},
+	"notification_install_message": {
+		"message": "Klikake seadistamiseks sellele teatele."
+	},
+	"notification_upgradedtostorage_title": {
+		"message": "'Tõlgi valitud tekst' on uuendatud v0.6'le!"
+	},
+	"notification_upgradedtostorage_message": {
+		"message": "Nüüd on valikud sünkroonis kõikide teie seadmetega! Halb külg on see, et peate laienduse uuesti seadistama :-( Klikake seadistamiseks sellele teatisele."
+	},
+	"notification_reorder_title": {
+		"message": "'Tõlgi valitud tekst' on uuendatud v0.7'le!"
+	},
+	"notification_reorder_message": {
+		"message": "Nüüd te saate seadistada, millises järjekorras me menüüs teile keeli kuvame. "
+	}
+}