Fix UMD globals for browser-like environments in types.
Merge pull request #572 from niant/master

Fix UMD globals for browser-like environments in types.
make R.times throw if given an invalid array length
Merge pull request #589 from davidchambers/times

make R.times throw if given an invalid array length
remove R.alwaysZero
add guidelines for contributors
micro-optimizing push
Merge pull request #593 from davidchambers/contributing

add guidelines for contributors
Merge pull request #594 from davidchambers/always-zero

remove R.alwaysZero
Merge pull request #592 from AutoSponge/master

micro-optimizing push