Formula.factory: raise on encountering non-Formula

Formula.factory naively assumed that any already-loaded constant
fed into it was a formula, with confusing results when trying to
`brew install` a name from the ruby stdlib.

Fixes #16284.
Fix Formula.factory for Formula subclasses

Fixes #16288.
openvpn devel 2.3-rc1

Closes #16027.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
groonga 2.0.9

Closes #16300.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
Redis 2.6.6

Closes #16297.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
node 0.8.15

Closes #16315.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
whirr 0.8.1

Closes #16319.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
vim 7.3.744

Closes #16321.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
nmap 6.25

Closes #16323.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
brew cleanup: don't remove higher version kegs.

* Use version compare to only remove kegs with lower version than the
  current one, not higher version which might be from someone's
  branch.
* Do the same for cache cleanup.
  - Be conservative so that if a name detected from cache file is not
    the same as its formula then don't clean it.

Closes #15914.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
pari: doesn't depend on X11.

References #15293.
redis: fixed redis.conf rename false positive.

Closes #16239.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
darner: add launchd and cleanup.

Closes #16240.

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

Closes #16329.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
Cassandra 1.1.7

Closes #16328.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
guile (devel) 2.0.7

Closes #16325.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
spatialite-gui: fix url

Closes #16326.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
cdo 1.5.8

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
cfengine 3.4.0

stripped patch

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
clhep 2.1.3.1

Signed-off-by: Adam Vandenberg <flangy@gmail.com>