Update gitignore settings with IDE and Mac file settings
First version, search and image details using event bus

Features:
- search for images
- show image details (only title and image) ; go back to search results
- handle errors and no results

This version uses the event bus scoped to Activity (and persisted through configuration changes)
heavily to handle view changes (message / result grid / image detail) "manually" (view are all part
of the same fragment and are "switched" by changing their visibility).
This is stable across rotation happening at any time.
Refactor with fragments

Use fragments for each of message / result grid / image detail screens, instead of the previous custom view
switching with backstack-like functinality through the event bus.
This allows to streamline the code, separate each screen rendering more clearly and build upon the framework
with state saving through arguments and navigation through the fragment transactions and the backstack.
Update icon

Replace default robot icon with a custom one.
Remove action bar
Move search bar a bit down
Expand / retract detail view title on click
Retrieve and show description and tags in image detail view
Slightly reduce search widget opacity
Prevent any grid element from being selected

Fixes the bug where the first element of the grid was automatically selected and when
tapping on it the click was only propagated after deselecting it (e.g. by starting to
scroll the grid view).
Retrieve and show image location in detail view
Use grid's item click listener instead of each grid item's click listener

Fixes the problems with the first item being selected by default and not receiving click
events until moving into touch mode.
Listen to location and add option to filter results close to current location
Update application theme

Use a more "modern" theme, visible especially on the checkbox.
Remove unused template files.
Change search bar background to dark.

Otherwise white checkbox wasn't visible anymore.
Support rtl languages in layout.