Updated pmath
Started implementing better FileManager on android
Fixed particle bugs
Creating directories and files now works properly on android.

Fixed/implemented everything so that it works on android. Windows filemanager still needs to be changed.
Also now always opens the files as read/write
Cleaned header and changed GetFileSize to return the current file size
Fixed windows implementation of FileManager
Merge branch 'feature/FileManager_overhaul' into develop
fixed testscene
Added missing implementation to RigidBody
Added customizable callback for Android's "Back"-button
Actually set the default color
Fixed volume controls in android
Possible to set rigidbody as a trigger
removed useless includes
Removed core project and moved files to more sensible locations
Moved texture to Resources
Removed audio project and moved the files to other projects
Removed leftover visual studio files
Fixed android build
moved shaders to resources