PDAL/PDAL — pull request #158 by c42f (2013-07-10 12:35:52+00:00)
Title: Fix various compiler warnings and minor bugs

Fix various compiler warnings emitted by gcc-4.6.3, some of which indicate bugs

* Mark boost and python headers as system headers to avoid a pile of
(mostly boost) warnings in headers we don't control.

* Remove assertion about the return value of memcpy, because memcpy
unconditionally returns the dest buffer regardless of success.

* Avoid unused variable warnings
- When building without hexer
- Due to variables only used in asserts
- Unused endianess variable

* Fix bug in las writer when reading uint8_t intensity from buffer,
which would have accessed a bogus pointer and caused a segfault.

Also fix minor memory leak of stage factories.