Adding support to parsedate in util module to understand the more idiomatic
dates 'today' and 'yesterday'.
Added unified tests and docstring tests for added functionality.
The use of "{datetime}" was unfortunate since I as a user never knew
if I was expected to do
hg log -d '>{2011-04-01}'
or
hg log -d '>2011-04-01'
The word "datetime" is also confusing -- calling it a date it much
simpler.
Remove the `install_package_data' subclass of `install_data' and use
the `package_data' functionality provided by distutils instead. As
package data must be located within the package directory, the data
files are now generated in the build directory.
To simplify the functionality of this change, the top-level `doc' and
`templates' directories have been moved into the `mercurial' package
directory.
