Added return InterMines over a given version

[zrthxn]

As suggested in issue #130, added code to filter InterMines by semantic versions and return only those which match the given condition. Implemented according to this.

Useage

There are 5 condition operators which are

gt (greater than)
gte (greater than or equal to)
lt (less than)
lte (less than or equal to)
eq (equal to)

These are sent with the desired version as follows

GET    http://registry.intermine.org/service/instances?version_api=gte-24
GET    http://registry.intermine.org/service/instances?version_intermine=lt-2.5.23

Caveats

The following things are desired but aren't implemented yet

• Doesn't yet support alpha,beta etc. in semantic versions (eg: 4.4.12-alpha)
• Doesn't yet support ranges, although that wouldn't need too much modification

[zrthxn]

"Catch all" in parts of version

Added a line to skip checking a part of the version if the condition includes "x" at that position.

Example

If the condition is gte-2.5.x all versions starting with 2.5 will be returned