[WIN32K]

[WIN32K]
Improve the code to enumerate monitors.
- Don't use custom MIN / MAX / ABS macros
- Calculate distance by r^2 = x^2 + y^2
- Use RECTL_bIntersectRect instead of code duplication
- Fix possible NULL pointer dereference
- pass bottom-right exclusive rect to IntGetMonitorsFromRect from NtUserMonitorFromPoint
- Don't handle MONITOR_DEFAULTTOPRIMARY and MONITOR_DEFAULTTONEAREST twice
- Use unsigned variables for unsigned values
- Don't check the result of a UINT returning function for < 0
- Improve readability

svn path=/trunk/; revision=49310