Reflect Master Core release v0.0.7

This version may not be backwards compatible, because searchtransactions_MP was
removed and the signature of listtransactions_MP changed.

Please note:
mastercore-php uses semantic versioning and v1.0.0 does not necessarily indicate
a stable release, but hints compatibility.

For more information about semantic versioning visit http://semver.org/.

Since v0.2 the following changes were made:

API calls changed:
- send_MP         $amount uses string (instead of float)
- sendtoowners_MP $amount uses string (instead of float)
- listtransactions_MP has a new parameter: $filter

API calls added:
- listblocktransactions_MP($block)
- sendrawtx_MP($sender, $rawtransaction, $reference, $redeemer)

API calls removed:
- searchtransactions_MP($address, $count, $skip, $startblock, $endblock)

Based on Master Core release v0.0.7:
https://github.com/mastercoin-MSC/mastercore/releases/tag/v0.0.7
https://github.com/mastercoin-MSC/mastercore/blob/0.0.7/doc/apidocumentation.md