Transition Commands

This pull request is here for all the command transitioning stuff.
After this lands, `ipfs2` will have merged back into `ipfs`.

Includes:

* 7a4491a - Added --mount flag to mount when running 'ipfs daemon'
* d3c9c59 - remove daemon node constructor
* f43954f - ensure node constructed is online for daemon
* 9ae420a - SizeSplitter fix: keep-reading until chunk full
* 607e4d3 - sharness tests back to cmd/ipfs
* 2b32e69 - remove ipfs2 from gitignore
* dc65e86 - makefile: revert back to cmd/ipfs
* ad3f3e0 - removed old commands files
* 5aaa45d - transitioned ipfs2 -> ipfs
* bd962b6 - test: lower key size for mount tests
* e24b09f - test: comment out extra output in add_and_cat