Support webkit gamepad api
Review changes
Update the simd.js

It is based on version https://github.com/johnmccutchan/ecmascript_simd/blob/14aa231d3c1021695ecee467ef35e5d61c8c669e/src/ecmascript_simd.js

Changes:
46620fd Add type check into SIMD operations.
1f29859 Fix float64x2.clamp implementation and add test case for it.
22b8ccf Use object properties instead of typed array as storage in polyfill
8941215 Changed conversion operators from SIMD.XXX.toYYY() to SIMD.YYY.fromXXX(), added 'select' operator for all types, added/updated tests
3eaaf69 Added reciprocal, reciprocalSqrt, shuffle, shuffleMix, comparison, and select operators to SIMD.float64x2
6f68238 Added SIMD.float64x2 (abs, neg, add, sub, mul, div, clamp, min, max, scale, sqrt, withX, withY, SIMD.float32x4.toFloat64x2)
Update SIMD.js code generation due to API update.
add javascript implementation of glutSetCursor function
fix indentation
handle all possible GLUT cursor value and throw an exception when an invalid one is provided
Addition of Module reference and cross linking to it from elsewhere. Removal from Interacting with code
Adjust clang version check to detect custom compiler vendor strings. #2698
Merge pull request #2699 from juj/custom_clang_vendors

Adjust clang version check to detect custom compiler vendor strings. #2698
Merge pull request #2694 from huningxin/incoming

Update simd.js and code generation accordingly
move alignment and type utilities out of Runtime, as not needed at runtime
add settings.js note of when we are running fastcomp
move imprecise bitops runtime utils into non-fastcomp
clean up dedup and set appearance in runtime
add structure alignment code to runtime only in non-fastcomp
add NO_FILESYSTEM and NO_BROWSER options, to reduce file size in cases where those functionalities are not necessary
Fixes to home page layout, size of inline code text, emcc final updates, improvements to tutorial and downloads
Merge pull request #2702 from hamishwillee/incoming

Numerous general fixes
update docs for -c