pythonCommand option added with GP_PYTHON_COMMAND as default

added pagerank example; phirl-improved

implement map-side join in gpextras; phirl-improved; pagerank

small changes and docs

mpaside join added

raff is slooow

default for flatten, phirl-improved example

bug fix: distinct and lc_collate=>lc_all

removing unneeded files

yow

cpu time info

a new test case and docs

docs

cleanup print statements and docs

docs