'ScanMulti' returns units if one command succeeds

The previous behavior was for ScanMulti to fail if any of the scanners
returned an error.

Signed-off-by: Samer Masterson <samer@samertm.com>
Add LICENSE to readme

Also included: TLDRLegal summary link.
BSD
MIT (oops)
Merge pull request #31 from xizhao/patch-1

Add LICENSE to readme
Merge pull request #30 from samertm/master

'ScanMulti' returns units if one command succeeds
we have a full docs site now (srclib.org)
Don't complain if not run in a repo dir, and only check repo once
fix version print call
fix `go vet` issues
rm unused CLI opts
linux binary links
installation instructions on homepage
fix check for exec.ErrNotFound
more informative err msg
remove python from the docs homepage temporarily
Added additional instructions for beginning emacs users, as recommended by @pathouse
use BSD-compatible "find"
Clean filepaths used to look up refs in the `src api` methods

This fixes an issue reported by Shiva where Ruby sources units whose
files are listed as ./file1, ./file2 (instead of just file1 and file2)
would not be matched when using `src api` methods.
Don't require rvm for Ruby toolchain in `src toolchain install-std`