Add Boot support

[seancorfield]

Make it easy to use Boot instead of Leiningen. I think boot show -C is a drop-in replacement for lein classpath.

[seancorfield]

Probably the cleanest way to do this is to look at the last part of the file path and check if it looks like lein or boot, and choose either classpath or show -C respectively.

[seancorfield]

Actually, since it is part of the config struct and not a separate argument, we could just use the presence of boot in that structure to determine it (and keep the default being lein).

[seancorfield]

Hmm, it's a config struct key for ioclj.cfc (and therefore FW/1), but it's an actual named argument for cfmljure.cfc itself.