Drop support for the original gyp?

[joyeecheung]

I was trying to merge gyp_llnode into scripts/configure.js and make llnode.gyp just binding.gyp (also in preparation for #147). I noticed that it would be easier if we just drop support for the original gyp and only supports node-gyp, which handles a lot of configuration done by gyp_llnode.

Note that on master, cloninghttps://chromium.googlesource.com/external/gyp.git to tools/gyp and use that to build llnode does not actually work at the moment, and it always gets deleted and relinked to the gyp in the node-gyp installation. (the first commit in #177 can fix that though). There are no issues for that so I don't think anyone actually uses the original gyp anymore?

[joyeecheung]

cc @indutny @bnoordhuis @hhellyer what do you think?

[bnoordhuis]

I'm fine with that.

[indutny]

👍