initial commit of CONTRIBUTING.md
initial commit of CODESTYLE.md
add translation contrib
_force_ contributors to branch from develop
fix PostTest tests
test reprocucing #1544
new testGetNullCustomField
fix #1544: null check customField
Super is now called at the end of onSaveInstanceState() in all reader fragments/activities that use it.
Updated build.gradle to use the latest version of Volley from the mirror at https://github.com/mcxiaoke/android-volley
Changed getFullSizeImageWidth() to accept a context which is then used instead of getActivity() when calling getDisplayPixelWidth()
Update CONTRIBUTING.md
Moved notes list cursor close to `onDestroy` of `NotificationsActivity`.

'onDestroyView' is called when a fragment is replaced which is what caused the exception. Fixes #1553
Merge pull request #1558 from wordpress-mobile/issue/1553-comment-detail-crash

Moved notes list cursor close to `onDestroy` of `NotificationsActivity`.
new test reproducing: #1549
Merge pull request #1557 from wordpress-mobile/issue/1551-npe-get-display-pixel-size

issue/1551-npe-get-display-pixel-size
fix testVolleyImageLoaderGetNullHost to check for a null host, not a null url
Merge pull request #1555 from wordpress-mobile/issue/1549-npe-network-imageview

issue/1549-npe-network-imageview
Merge pull request #1534 from wordpress-mobile/issue/1366-contributing.md

fix #1366 contributing.md
Use the old manifest merger, and upgrade to gradle plugin 0.12