Full Rewrite (except for FAQ, minor changes there)

 - Cleanup
 - Rewrite of most of document
 - Added GitHub Flavored Markdown
 - Contributors Table
 - Tl;DR
 - Misc.
 - etc.
Removing pointless forced overwrite point check.
Making sure last forward slash is removed from input path.
Merge pull request #20 from irrequietus/master

Forward slash and force overwrite checkpoint fixes.
Preserve extraction semantics without resorting to tar stripping.
Merge pull request #21 from irrequietus/master

Preserve extraction semantics without resorting to tar stripping.
Deferring output directory after -f check has taken place.
Target directories must always exist and -f should not create them.
Merge pull request #22 from irrequietus/master

Making -O and -f modus operandi semantically consistent.
Simplifying and refactoring logic, alignment edits, empty semantic rewire.
Making things more homogeneous in checks, some space removed.
Merge pull request #23 from irrequietus/master

Simplifying and refactoring lrztar logic.
Update changelogs.
Bump version number to 0.616
Provide a helper function to round a value up to the nearest page size for malloc optimisations.
Increase the compressed buffer size given to libzpaq in case of incompressible data since it does not check if it's trying to write beyond the end of the buffer.
Round up compression and decompression buffers to page size since malloc will allocate them that large anyway.
Fix 'Failed to malloc ckbuf in hash_search2' with very large files.

lrzip was trying to malloc() enough memory to fit the entire length of file it was going to hash, instead of just the size of one chunk. This caused problems when combined with extremely large files.
Merge pull request #27 from Maeyanie/patch-1

Fix 'Failed to malloc ckbuf in hash_search2' with very large files.
Add cksems to util.h