Merge branch 'master' into devel

Brings changes done on release-0.5.3 into devel.
find_mongo_pids: Fix regression in 203a82d.

Don't consider "ps" stderr to be an error. This occurs on OSX Mountain Lion if
DYLD_LIBRARY_PATH or a similar env var is set, and is harmless.
Bump version number to 0.5.4 and write History.md.
find_mongo_pids: Fix regression in 203a82d.

Don't consider "ps" stderr to be an error. This occurs on OSX Mountain Lion if
DYLD_LIBRARY_PATH or a similar env var is set, and is harmless.
Merge branch 'release-0.5.4'
Merge branch 'master' into devel
Add emacs TAGS file to .gitignore.

Suggested by naomi.
Fix spelling error

Missing 'n'.
Specify that Bootstrap is a front-end framework

Taken from the Bootstrap homepage: "Sleek, intuitive, and powerful front-end framework for faster and easier web development."

Nitpick. There's no such thing as a "UX framework", and Bootstrap also provides more than just UI widgets, so I figured it would probably be best to just use the same description Twitter chose.
Optimised images

Originally from https://github.com/meteor/meteor/pull/569

Reworked to:
- apply to soma.png, not soma.jpeg (file was previously misnamed).
- don't touch bootstrap's glyph image. It would cause conflicts later, and is not neighborly.
Add underscore as dependency for Spark

Fixes #587
Added Meteor._debug function to dependency list
Merge branch 'pr-588' into devel
spiderable: Correctly kill phantomjs after timeout. Fixes #571.

The previous version only killed the wrapper bash script, not the child. We now
work around the broken (socketpair) stdin presented to Node's child processes by
using a bash heredoc rather than "cat |"; this means we can use exec, which only
gives us one process to clean up.

While we're at it, simplify code by switching from child_process.spawn to
child_process.execFile, which does the work of capturing stdout and setting a
timeout for us automatically.
livedata client: Factor out "stringify message and send it" into a helper.

(Extracted from ddp-pre1 branch.)
Maybe fix #555.
Add test for fix to #555.
Merge branch 'quiesce-fix' into devel
Workaround weird header issue in firefox. Fixes #553.
Ignore example directories that begin with a period. This avoids 'meteor create --list' displaying .gitignore.