Fix indenting of HTML (closing) tags for instance. Fix #1294

The indentation level is not anymore reduced by adding a new line,
which previously caused multiple reductions of the indentation level.
This fixes the behavior of HTML closing tags, which currently
"jump" backwards if you try to move them down.
add links to build error reports in build docs
Merge pull request #2493 from atom/iz-update-build-docs

Add links to build error reports in build docs
Merge pull request #2164 from steffengy/fix-indent

Fix indenting of HTML tags for instance. Fix #1294
Check for that grunt command exists before spawning
Upgrade to bracket-matcher@0.42