bin: add --reverse flag
Add "greater than range" function, gtr(v,r)

gtr(version, range): Return true if version is greater than all the
versions possible in the range.
style in replaceCaret
style in test/index.js
add ltr(version,range)

Also, the utility function that gtr and ltr use,
`outside(version, range, hilo)`
v2.2.0
Merge remote-tracking branch 'upstream/master'

Conflicts:
	README.md
	semver.js
	test/gtr.js