Makes style for text input closer to app search

Some style fixes so the text input resembles the app search better:
  - Tracks mouse hover;
  - Fixes transition-duration, according to css3 the value is expressed
  as a time;
  - Changes selected color and caret color so they match the app search;
  - Styles the hint_text using the pseudoclass :indeterminate. That way
  the typed text isn't a brighter color after a mouseout followed by a
  mouse over;
Replaces tab by spaces
Merge pull request #83 from larissa/master

Makes style for text input closer to app search