meqtrees: Add without-symbols option

The formula now supports three cmake build types: Debug, Release and
RelWithDebInfo (the default). Debug produces unoptimised code with
debugging symbols, Release has -O3 optimised code without symbols
and RelWithDebInfo is a happy compromise with -O2 optimised code and
debugging symbols.
wcslib 4.16

WCSLIB 4.16 includes a new error diagnostics system contributed by Michael Droettboom that should make it easier to track down problems, particularly those caused by bad headers. The test suite is also less garrulous, tests that succeed now simply report PASS, and there were several other improvements.
wcslib: Add tests

These test are usually run by calling "make check" in the source
directory. The Makefile contains quite a bit of intelligence and this
had to be captured in the formula.
purr: Extend icon path patch

Extend patch to add Homebrew-specific icon search directory to a
second function used in MeqTrees meqbrowser 1.2.1.
tigger 1.2.2

Fix patches to work both with HEAD and the last release (1.2.2) by
leaving out part of patch 2 for a non-existent file in version 1.2.2.
This required moving the patches from DATA to gist URLs to be able to
cherry-pick them.
cattery 1.2.0

Fix formula to work with HEAD as well as version 1.2.0 by ignoring
Scripter directory that does not yet exist in version 1.2.0.
meqtrees: Fix patches for 1.2.1

Fix patches to work both with HEAD and version 1.2.1. This required
moving them from DATA to gist URLs to allow cherry-picking them.
Add a patch needed to build version 1.2.1. This still has a problem
with meqbrowser not connecting to meqserver via Unix sockets.
obit: Avoid spilling file handle