removed useless find* files. Renamed Coin and SoQt so that it matches the system find files and config files

* removed global lock
* fixed warnings

* all camke module files are now in simox/CMakeModules
* FindBullet also uses Bullet_DIR to detect bullet
* Simox checks whether Bullet uses single or double precision
* removed the option SimDynamics_USE_BULLET_DOUBLE_PRECISION
* Set default for Simox_BUILD_SimDynamics to true (a warning will be printed if bullet is not found and SimDynmics will not be build)

Some were already using it and this should be uniform to work properly.