Fixed a couple of bugs when overwriting data using hex editor

git-svn-id: https://yabause.svn.sourceforge.net/svnroot/yabause/trunk@3093 d7be59e3-070e-4b9a-85a1-4646befae34d
Fixed blending for pixels at the same priority.

The software renderer had a bug were pixels would overwrite
previous pixels at the same priority level instead of blending
with them.

This fix the shadows in Spot Goes to Hollywood.

git-svn-id: https://yabause.svn.sourceforge.net/svnroot/yabause/trunk@3094 d7be59e3-070e-4b9a-85a1-4646befae34d
Fixed bug when trying to remove memory breakpoints on qt port

git-svn-id: https://yabause.svn.sourceforge.net/svnroot/yabause/trunk@3095 d7be59e3-070e-4b9a-85a1-4646befae34d