See the attached files for a diff between 1505 and 150501 source directories.
Need to understand the changes and why they were needed.
From OP 150501 Release Notes:
— RELEASE-15.05.01 HOTFIX — Banana Split —
This release fixes an important bug. All Revolution hardware running 15.05 should upgrade to 15.05.01. Note that this is a hotfix; it can simply be flashed without an erase settings. Furthermore, please review your vtolpathfollowersettings:HorizontalVelMax; a value of around 4m/s would be more appropriate for preliminary trialing of a new release and will be changed in future.