Upgrade both site and docs to Bootstrap 3 (flatly)

Critical dependency on this site merge and the ngdocs merge being done at the same time.
Create translation entries for pt_BR
fix(uiGridCell): Use promises for tmpl processing

Issue #1712 demonstrates a race condition where a column's
compiledElementFn is attempted to be called before the cellTemplate is
present, e.g. in the case of a template fetched over the network. This
causes the function to not be present and an exception to be thrown.

This changes fixes this by added a getCompiledElementFn() method to
GridColumn, which returns a promise that is created in the
defaultColumnBuilder(). It gets resolved in
Grid.preCompileCellTemplates(). uiGridCell now uses this promise if the
function is not present at pre-link time.

Added tests for getCompiledElementFn() and getCellTemplate()

Fixes #1712
Merge pull request #1749 from raulcesar/translation_pt_BR

Create and correct translation entries for pt_BR
Merge pull request #1732 from KiwiNiksta/flatly-only-bs3

Upgrade both site and docs to Bootstrap 3 (flatly)
Merge pull request #1752 from angular-ui/fix-http-templates

Fix url-based templates by using promises to retrieve the compiled function
Update to new grunt-ngdocs for bootstrap update
chore(Site): Add ngAnimate to index for menu animations
Fix #1753 (colMenu): size correctly with animations, hide on scroll or drag
Merge pull request #1755 from PaulL1/1753_column_width_animations

Fix #1753 (colMenu): size correctly with animations, hide on scroll or d...
fix(uiGridUtil): getBorderSize() missing "width"

The correct property name to use is "borderWidth", not just "border".
"border" works in Chrome but was breaking in Firefox.

Also had to change .ui-grid-header's box-sizing to content-box so IE11
would include the border in height calcs. AND finally IE11 was returning
fractional heights so Grid parseInt()s the returned values.