Various uninitialised variable fixes

sky.cpp: m_bgcolor.getAlpha() was being used before initialised

mesh related: m_highlight_mesh_color was being used uninitialised
Update the cURL the buildbot uses to 7.38.0
Custom collision boxes node property.
Basic reformatting with astyle
-- additional formatting will be modified, manually, as the need for it is encountered
Start "outlining" what a MinetestApp class might look like
Add MinetestApp::shutdown()
Converted class member functions to camelCase and created protos for new functions
First stage of connect to server done
Add get itemdefs/nodedefs/media code
Init clouds, camera, sky, init GUI, HUD
Input handling
Client events, camera, sound, draw
Fix wield hand getting stuck digging and add debug text back
Fix FPS
Added profiler graph back
Fix FPS issue
Need to work out what went wrong and clean up the copy/paste stuff
Annotate
Various:
Rewrote limitFps()
Limited scope of some variables
Jitter calcs