Cleaning up unused commands, adding documentation

Added:
parallel-xargs (alias: x)

Renamed:
gurl => gcurl

Changed:
lc: Only reads from stdin per tr
uc: Only reads from stdin per tr

Removed:
execlist (alias: els)
execlistcontext (alias: elsc)
execfind (alias: efind)
execcat (alias: ecat)
__repo_ps1 (already deprecated)
Removed: auto-sync
Fix open and copy/paste commands
Move hosts-rebuild, make ips cross platform
Fix references
Update git-prompt.hs
Move p alias