[Tizen] Content API - Part 3

Added support for Tizen filters (AttributeFilter only). The rest (Range and Composite) are coming later.

Added also support for media type specific attributes for audio, video and image types.

Changed some types to more convenient ones f.ex timestamp to string.

Added filtering features to examples/content.html test page.
Merge pull request #278 from poussa/content-3

[Tizen] Content API - Part 3
Bump version to 0.49
[Application] Add current application exit/hide support

The supported APIs are listed below:
Application.hide/exit

The implementation leverages running application object exported by the runtime
process on the DBus session. The "Terminate" and "Exit" methods of it only
permit the launcher process to access.

Supplement Application example for new added APIs are also added.
Merge pull request #289 from seanlong/app_dev

[Application] Add current app exit/hide support
Bump version to 0.50
[Tizen] Don't throw exception when empty files are read

This patch removes check that throws exception when empty file is read.
Merge pull request #293 from alexshalamov/fix_read_empty_file

[Tizen] Don't throw exception when empty files are read
[Tizen] Add support for missing virtual roots

This patch adds support for missing virtual roots:
wgt-package, wgt-private, wgt-private-tmp and ringtones.