murmur_hash3() to avoid violation of the strict aliasing rule.  In particular,
the previous version didn't work correctly in gcc 4.7.2 when optimizations were
enabled.

the mean average precision when matching SURF descriptors
by about 2%.

region and therefore finds more interest points.

in addition to just raw ranking accuracy.  This changes their return types
from double to matrix<double,1,2>.

so that we avoid a common cmake warning.

ASCII matrices using the format used by operator<<.

to not redraw overlay lines correctly in certain cases involving non-default
zoom levels.

by Isaac Peterson.  The bug caused the program to deadlock if signal() or
broadcast() was called at exactly the same time a wait_or_timeout() funciton timed
out.

array2d type image (not the one that draws onto a GUI canvas object).  The bug
triggered whenever a perfectly horizontal or vertical line that extended
outside the image was drawn.  This has been fixed.

safety.

parallel_for_blocked()