Change Travis CI script to run make distcheck
Do not touch version-vcs.h if we are not in a Git repository

This fixes `make distcheck` which previously failed on the
`gitversion` rule.
Makefile.am: Add rule so make knows how to generate version-vcs.h
Update MSVC project
Separate data integrity check
Fixed: animation table loading
Remove DOS sprite processing to data-source-dos
Fixed: waves drawing
Enhanced resizing and fullscreen support
More accurate viewport drawing
Separate sprite cashing and reimplement it on C++
Some cleanup
Native image cashing
Rename SDL specific files
Remove frame reusing

May redraw popup only when it’s really changed
SDL drawing optimized

Most of time game was copy images to video memory
Sprite caching optimized