Perform post-installation checks if a formula is installed.
Added for brew test-bot to be able to fail on bad Cellar installation.

If linking fails,  won't try to re-install the plist.

Closes Homebrew/homebrew#20843.

Closes Homebrew/homebrew#10817.

Closes Homebrew/homebrew#20713.

Closes Homebrew/homebrew#20711.

Closes Homebrew/homebrew#18303.
Closes Homebrew/homebrew#20726.

Prevents this character from being changed when resaving this file
with TextMate (1) on Snow Leopard.

Closes Homebrew/homebrew#20715.

* Fix a comment; we pass in formulae not names
* Don't pass the formula to factory; this is just a pass-through
* Move require to top-level

Closes Homebrew/homebrew#20357.

Fixes installation of e.g. ScriptFileFormula/denominator bottles.

An "optional build-time dep" is unlikely, but possible, and I happen to
notice this wasn't handled correctly while digging around in the deps
code over the last few days.

Fixes Homebrew/homebrew#19857.

It doesn't really make logical sense that this method returns both the
fetched path (or sometimes nil!) and the downloader, so just return the
path (again, or nil!) and callers that want the downloader can ask for
it separately.

Fixes Homebrew/homebrew#19107.

Fixes Homebrew/homebrew#17010.

Sometimes we may want to run commands after bottle installation (such as
creating directories outside the Cellar) so this method allows us to do
so.

Closes Homebrew/homebrew#18382.

We want to notify users that non-/usr/local installs may result in some
bottles being not used.

References Homebrew/homebrew#18540

Fixes Homebrew/homebrew#18631.

- Store in the tab if a bottle was poured for the build.
- Add an additional line of output to `brew info` outputting whether
  the formula was built from source or poured from a bottle.

Closes Homebrew/homebrew#18430.
Closes Homebrew/homebrew#18475.

Pending a decent fix.

Fixes Homebrew/homebrew#18540.

This has two parts:

1. Bottles are temporarily relocated on bottling and tested if that is
sufficient for them to contain no longer reference the prefix or
cellar. If so, they are marked as relocatable.
2. On installation if bottles are marked as relocatable they will be
relocated using install_name_tool to the current prefix and cellar.

Closes Homebrew/homebrew#18374.

Closes Homebrew/homebrew#16344.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Allows access to the Ruby path. Needed for Linux
porting.

Closes Homebrew/homebrew#18333.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>