add missing return values in safeRequestAnimationFrame,safeSetTimeout,safeSetInterval
Merge branch 'incoming'
Commit the source-map library.
Implement basic source maps. Closes #1252.
Add check for keep_llvm_debug + minor touchups.
Add test for source maps.

Tweak behavior of post_build; the `post2` hook now expects a function.
Ensure line numbers are the same in HTML.

Chrome and FF seem to be able to handle the extra empty lines, but no
harm making things more accurate. One thing less to worry about when
debugging.
Fix source map line numbering for inline scripts.
Add test for HTML source map generation.
IMPROVED: ADDED resizeListener that invokes the GLUT.reshapeFunc if specified
BUGFIX: several SDL related bugfixes
ADDED: GLUT_SCREEN_WIDTH + GLUT_SCREEN_HEIGHT in glutGet
CHANGED: removed "MADE"-tag from comments
IMPROVED: removed empty line and white-space at EOL
Lay the groundwork for optimized source maps.
Delete uglify code that was only needed for compression.

This makes it easier to reason about the remainder...
Map source lines for assignment statements.
Move source mapping files into their own folder.
Update the source-map library.
Implement source maps for optimized builds.