Mercurial 2.5

Closes #17578.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
ivy 2.3.0

Closes #17577.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
gnu-smalltalk: generational GC requires libsigsegv

In 64 bit, --without-libsigsegv implies --disable-generational-gc

The build was failing for me, now at least it builds by disabling
libsigsegv it seems to work (on small programs)

Closes #17576.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
leveldb: also build the leveldbutil

The tool is really useful to dump the contents of leveldb
databases

Closes #17581.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
Xcode.version: return dunno as a string and not a symbol
XQuartz.version: return dunno as a string and not a symbol