Create Pictures directory if it doesn't exist

Didn't exist on one test device - images were stored on phone or
sdcard DCIM, but the Pictures folder didn't exist
Merge pull request #27 from bentleyo/patch-1

Create Pictures directory if it doesn't exist
Added WRITE_EXTERNAL_STORAGE permission to Android
Update README.md
Ported the plugin to WP8
+ Added entries for WP8 version to plugin.xml
Fixed the version and description in plugin.xml
Merge pull request #35 from Crulex/wp8

Ported the plugin to WP8
Add ID_CAP_MEDIALIB_PHOTO for wp8
Update README.md
Update plugin.xml
Update repo