Handle both :variable and {variable} parameters

[Croebh]

Converted it to a foreach loop over an array, which implements the existing issue as well as allows for future expandability (either in the base plugin or by local users)

Fixes #11

[pahofmann]

This would be really helpful for me, any idea when this will be merged?

[ctmay4]

Another +1 for me. This would make this plugin much more useful!

[jpabst]

The issue with just the prefix ':' is that it suffers from multiple issues:

• incapable of having multiple params if one is a prefix of another (e.g. :dummy1/:dummy10)
• incapable of having a param 'nested' in as a partial word (e.g. /:VARfather where possible VAR values are: "", "step", "adopted", "biological"

Please merge this in.