Updated `brew graph`

Changed 'graph' command to show only installed by default. Prettified
resulting graph.

By default, the `brew graph` command would output a dependency graph for every
formula it knew about. Now it only outputs a dependency graph the for formulas
installed. If you want to see the graph for all formulas, use `brew graph
--all`.

Additionally, the old version of the graph command would filter out any
formulas without depdency connections. The updated version now only does this
if calculating dependencies for all formulas via the `--all` flag.

Finally, the resulting graph has been redesigned to be simpler to read. All
formulas which have no other formulas depending on them (i.e., root nodes) are
aligned to the left. They are also outlined in a light grey box, which is
labelled "Safe to Remove". As implied, all of the formulas in this box can be
safely removed without breaking other installed formulas; all formulas outside
this box have at least one installed formula depending on them. This new graph
style is surpressed if the `--all` flag is used.

Closes #18282.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
subversion: install svnmucc and other svn tools

Some useful tools can be installed through 'make install-tools'. Among
them, the following five binaries have filenames with the prefix 'svn',
and won't conflict with binaries form other packages. So it's safe to
install these tools by default.

 * svn-populate-node-origins-index
 * svn-rep-sharing-stats
 * svnauthz-validate
 * svnmucc
 * svnraisetreeconflict

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
go: Correct file name for zsh completions

Previously, the completion file was installed as "_go", which by
convention means that it will be loaded by compinit.  But this file
does not have the #compdef tag, so this doesn't work, and nothing in
the file indicates that it is supposed to be used that way.

Therefore, install the file under the original name "go" to indicate
that you need to load it manually (as the comment in the file
suggests).

Closes #18752.
lftp: use std env

Closes #18749.
CGAL: Eigen3 and LAPCAK build options added

Closes #20160.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
rbenv-bundler 0.96

Closes #20149.
fix fishfish alias
nzbget: fix arity of libpar2 initializer
nzbget: don't override #inititalize at all
deps: move recursive_deps_tree into Homebrew module