Merge pull request #2 from takikawa/master

Convert to pkg format
xalloccolor returns a Status

(I did not use it yet though)
XRaiseWindow and XLowerWindow must return _void
Install instructions
add warning
XCheckTypedEvent now returns _bool instead of _int
wrapper for the finalizers.
Should be simpler to use and should avoid bugs.
add cblock->vector/finalizer
remove trailing spaces
remove trailing spaces
fix xtextpropertytostringlist (finalizer)
fix getwindowproperty...
Update info.rkt