SailfsihOS support

[savegame]

Its would be nice if your engine will support SailfishOS.
I get some code from PR #117 and fix it. Now it build binary for SailfishOS properly ( inside SailfishOS Build Engine virtual machine)
I want add full support of SailfishOS to your engine ( screen rotation, sound, maybe gyroscope, accelerometer, lock screen blanking), and add ability to build application from host system ( using SailfishSDK tools ).
but now i have few questions about screen rotation:

1. In SailfishOS, system not rotate application render, if we use not Qt application ( like SDL2 ), that mean we need render target for all application content, and we should rotate it inside oxygine. My question is: do oxygine render all in RT, or it draw any sprite directly to screen buffer? If it use RT, please tel me where it render, i just add special shader for it, for rotation rendered picture inside shader, and change its size ( if application is use landscape mode ). If oxygine not use main RT for all content, where is the best place for adding that RT ( maybe inside set global RT in core::beginRendering, then draw that global RT in core::swapDisplayBuffers ) ?
2. is oxygine have some enums for current screen orientation? If not, where i should add that enum? it need for locking screen orientation to landscape/portrait mode for applications in SailfishOS

[savegame]

maybe just need add own PostProcess? (PostProcessTween) ?