Don't escape slash; it's unnecessary

Fixes #1444.

Test Plan: grunt fasttest
Stop running so many things in travis

We're not actively looking at most of these and they take up valuable
job time.
Give context for owners of compenent instantiations with propType errors

See modification to the test-file: Basically we add a small hint at the end
of the error warning for propType errors to help identify which instantiation
of the component at hand is faulty.
Clarify when getDefaultProps is called

Fixes #1778.
Fix spelling/grammar in test comment
Fixing grunt jsx task in Windows

Spawning node directly instead of relying on shebang in the jsx-internal script

Fixes #1292
Merge pull request #1779 from spicyj/spell-gram

Fix spelling/grammar in test comment
Merge pull request #1780 from jbrantly/issue-1292

Fixing grunt jsx task in Windows
Update npm dependencies [skip ci]
Merge pull request #1461 from spicyj/no-esc-slash

Don't escape slash; it's unnecessary
make invariant show formatted actual errors in all unminified environments

Because we can have !__DEV__ but unminified, we still want to see the
message in those cases.
Give useful error when using two copies of React

If we don't error here, we end up with a confusing error later on in this.getDOMNode() where ReactMount doesn't have the proper container registered in its object.
Merge pull request #1531 from spicyj/two-face

Give useful error when using two copies of React
Also list <form> in error message as possible culprit