Fix ReactTextComponent display for React 0.11+

Fixes #44.
Merge pull request #45 from spicyj/rtc11

Fix ReactTextComponent display for React 0.11+
Only set DEVTOOLS_INJECTED_SCRIPT if successful response

Fixes #41 (probably)
Merge pull request #43 from zpao/silent-response-fail

Only set DEVTOOLS_INJECTED_SCRIPT if successful response
Merge remote-tracking branch 'upstream/master'