Merge pull request #129 from thephpleague/pr128

PR128 additions

Merge pull request #126 from thephpleague/issue125

Fixes to the query functions.

Merge pull request #124 from thephpleague/issue123

Issue123 - Support `signatureKey` for HMAC SHA-512 signing (SIM and DPM)

Update README.md

Merge pull request #98 from samlitowitz/issue-97

Issue 97 Thank you,

Merge pull request #94 from samlitowitz/issue-93

Issue 93: Support CaptureOnly

Merge pull request #80 from Mark-H/patch-1

Fix typo in readme

Merge pull request #46 from fenzig27/pr-invalid-shipping-firstname

Fixed getShippingLastName() was being used to seed shipTo->firstName.

Merge pull request #39 from thephpleague/issue38

Issue38

Merge pull request #34 from anushr/xml-api

Migrate to XML API for AIM + CIM support