clojurescript 1853 (new formula)

Closes #21744.
snzip 0.9.0 (new formula)

Snzip is a command line tool for using snappy.

Closes #19476.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
snzip: improve test.
Pcre++: rename man page to avoid conflict with pcre.

* The man page of pcre++ is named Pcre.3, while there is one named
  pcre.3 in pcre package. This is problem for case-insensitive file
  system which is widely used across Mac OS X systems. Rename it to
  pcre++ and add caveat about this change.

Closes #21968.