Merge pull request #19 from wiggzz/master

Pulling in changes in preparation of merging to master.
Merge pull request #20 from Storj/devel

Finally merging in development branch
added comment for source of code in clz.h
added copyright notice for pycxx
fixed typo
removed file keyword from example.
added security features to heartbeat for safe deserialization
more security enhancements.
added stdexcept for compilation on linux
Merge pull request #21 from wiggzz/devel

Security enhancements and some small bug fixes.
added proof size check to return false instead of throwing a runtime error on proof invalid size.
Merge pull request #22 from wiggzz/devel

added proof size check to return false instead of throwing a runtime err...
added optimization for heartbeat serialization so that keys are not transmitted for a public heartbeat, since they would be zeroed out anyway.
Merge pull request #23 from wiggzz/devel

added optimization for heartbeat serialization so that keys are not tran...
fix for more sensitive gcc compiler
Merge pull request #24 from wiggzz/devel

fix for more sensitive gcc compiler
modified Merkle so that blank subclasses can be created with no parameters on the constructor.
fixed some typos
added check for branch verification invalid leaf
added test for invalid leaf in branch verification