Vega Strike Code

Update configure.ac script to better check PNG support in light of recent incompatibilities.

Ticket #18: removed use of deprecated libpng functions

About 1/6 of the original cmake warnings squashed. Only a few files with warnings remain.

About another 1/3 of the cmake warnings squashed. As per my previous commit, this needs reviewing and fixing by someone more familiar with the code. There are BUGS here. In mesh_gfx.cpp, for instance, there are two switch statements with conditions but where nothing is done in the bodies. Look at the diff and search for FIXME for bugs; some of which I addressed without knowing what I'm doing, and some of which I couldn't.

merging with safemode branch -r12684

Replace obsolete debugging calls in vsimage and one annoyance in unit_generic, fix vs_dprintf

merging trunk -r12682

Here's about 1/3 of all the warnings from cmake squashed. WARNING: There were/are many BUGS which I could not properly fix; namely variables that were declared without initialization, then initialize inside some conditionals or cases but not others, and subsequently used. In 90% of the cases I initialized them to zero, or to 0.0f, or to enum Ok, etceteras; but this NEEDS attention from someone more familiar with the code. Check the diffs. Many files like that. Warnings from the collision library were made to shut up with a pragma. They rely on sizeof(float)==sizeof(int) and (int&)float(0.0f)==int(0), which happens to be true, currently, with AMD athlons and compatible cpu's. Terribly incorrect library, tho.

Removed obsolete cubemap texture transfer debugging messages.

remove needless debugging printouts