Varnish 4.0.0
varnish: add 4.0.0 bottle.

Closes #28410.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
neo4j 2.0.2

Upgrade to Neo4j 2.0.2

Closes #28416.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
gcc 4.8.2 (new formula)
shared: don't warn about non-Apple compilers now.
Add core GCC formula as a new compiler.

This means that `:gcc` no longer implies the Apple GCC 4.2 but instead
uses the GCC from core.
Use gcc instead of apple-gcc42 when needed.
Migrate apple-gcc42 back to homebrew/versions.