calculate two Ranges intersection.

[xice-blue]

I have two case need deal:
3 modules dependency X module:
1.
'x': '~1.1.0'
'x': '~1.1.5'
'x': '1.1.10'
or
2.
'x': '~1.1.0'
'x': '~1.1.5'
'x': '1.2.1'
Case 1 need get X module version is 1.1.10, and case 2 throw Exception about version mismatching.
So I extend function 'intersections' to deal these cases.

[coveralls]

Coverage decreased (-0.1%) to 94.526% when pulling 33e9be7 on xice-blue:master into 8fff305 on npm:master.

[rtfpessoa]

I think this is the same I have here: #187 waiting for merge for a while.

[xice-blue]

@rtfpessoa your function return is true or false, I need return intersection.
For example: range '~1.1.0' and '^1.0.0 < 1.1.5', it will return '>=1.1.0 <1.1.5'.
And I can get more range's intersection.

[rtfpessoa]

You are right. I think I misread the description.

[adam-stanek]

Please add test for ['^1.2.1', '^1.2.5', '>=1.2.5 <2.0.0']. It doesn't seem to be working.

[isaacs]

Landed and published in v5.4

[isaacs]

Er, another implementation landed. Not this one.