Moves the particle graphics bridges to Particles.

The graphics bridges are contained in header files,
such that they are only compiled when the
corresponding graphics systems are used.
Currently, OpenGL1 and OpenGL3 have bridges
provided. This ensures that a graphics bridge
that is incompatible with a given graphics system
(like graphics bridge OpenGL3 with graphics system
OpenGL1) are not compiled together.

The graphics bridges are written purely in headers.
This is done since .cpp source files are compiled
before knowledge which graphics system has been
chosen is available.

The OpenGL3 graphics bridge has furthermore been
updated to use OpenGL 3.0+ features, such as shaders
and VBOs.
Added check for minimum OpenGL version in graphics bridge.
Fixed oldtonew in particle bridge OpenGL3.
Implement file_find* functions and environment_get_variable.

Apparently, these functions are declared but not implemented. That's an error in my book. I've committed an implementation from the compiler code; hopefully this doesn't break anything, because I can't test on Windows.
Fix build error in file_manip.cpp
Fixed texture setting bug
Merge branch 'master' of github.com:enigma-dev/enigma-dev
Added fps uncap in above 170 room_speed. Removed room caption setting (temporary measure) as it was obliterating the fps. Changed model drawing back as it was correct before.
Moved particles to namespace enigma_user.
Merge remote-tracking branch 'upstream/master'
Merge pull request #164 from forthevin/master

Fixes particles; refactors to use bridges in particles; moves to enigma_user
Added room caption back in for Windows. Note on other platforms screen_refresh and io_handle need to be updated also to add in room_caption / mouse update.
Set depth buffer clear to only happen in d3d mode
Optimized OpenGL3
Models are much faster now, and I cleaned up a lot of buggy code, should be
more stable now too.
Fixed Plugin Bug
There was an issue with exceptions when hit the compile button when its already
compiled, so I made it disable them like the ones in the menu bar.
Fixed Regression
I had accidentally reverted some of forthevins changes to my graphics system.
Merge pull request #170 from RobertBColton/master

Optimized OpenGL3
Moved OpenGL1 Mesh Code
Split it out of GLd3d.cpp and put it in GLmesh.cpp as well as the headers, to
make it consistent with other graphics systems.
Merge pull request #172 from RobertBColton/master

Move OpenGL1 Mesh Code
Used usleep in fps-handling for Windows.