Fix: Install quark dependencies with refspecs

[crucialfelix]

Installs dependencies (including their dependencies) instead of just checking them out and linking them.

Fixes #1377

Parses refspecs in dependencies as advertised.
Also catches named quarks that are not found, posts the ERROR and returns nil.

Quark.parseDependency("Bjorklund");
Quark.parseDependency("DoesntExist");

Quark.parseDependency("crucial-library@tags/4.1.4");
Quark.parseDependency("crucial-library@tags/bad-tag");

Quark.parseDependency("DoesntExist@tags/4.1.4");

Quark.parseDependency("UnitTesting" -> 1.0)
Quark.parseDependency("DoesntExist" -> 1.0)

Quark.parseDependency(["UnitTesting", 1.0, "svn://sourceforge.net/etc/usw"])
Quark.parseDependency(["DoesntExist", 1.0, "svn://sourceforge.net/etc/usw"])


Quark.parseDependency("https://example.com/_404_.git");

Quark.parseDependency("https://github.com/crucialfelix/Mx.git");

Quark.parseQuarkName("https://github.com/crucialfelix/Mx.git")

[scztt]

I mentioned this to you in an email, but this is the beginning of the test quite I was using to test quark download / installation / dependencies:
https://gist.github.com/scztt/dda6df4046a5311f48f6
It should work as-is with your pr? I haven't tried it yet, I will tomorrow if I have time.

[crucialfelix]

to test this PR we just need to run the parseDependency checks I showed above.

monkey testing it against the whole quarks is also a good idea, but I think we can do that later.

[scztt]

@crucialfelix - spent some time testing this, seems to be working fine. Merging so we can get alpha1 out.