Fix depecrated sourceMappingURL syntax

This will remove an error message about using old syntax in debug builds.
Merge pull request #2165 from juj/fs_element_size

Fullscreen element sizes
Merge pull request #2162 from TV4Fun/syntaxupdate

Fix depecrated sourceMappingURL syntax
make js optimizer max chunk size customizable
make sdl canvas copy warning a one-time thing; fixes #2167
more warnings on source versions not matching, plus testing
Fix bug that caused emscripten_get_callstack to not truncate the output buffer. Add test. Closes #2171.
fix test_source_map
Bring ChangeLog up to date to latest tags.
support -Os and -Oz as arguments to emcc
fuzz -Os and -Oz as well
improve other.test_os_oz
run -globalopt when NO_EXIT_RUNTIME, to get rid of global initializers entirely in some cases
make NO_EXIT_RUNTIME work properly with llvm lto
Remove Emscripten-specific workarounds from the sqlite3 test.
Merge branch 'incoming' of https://github.com/kripken/emscripten into incoming
Make this testcase pass the verifier.
fix glCompressedTexSubImage2D; fixes #2173
Merge pull request #2174 from sunfishcode/incoming

Two minor testsuite cleanups.
add a test for fastcomp issue 24