add translitcodec to contrib
use translitcodec for urlify
remove unnecessary imports
convert session to dict before pickling

Session was constantly being pickled without converting to dict as it
should be.
fixed a bug in SQLFORM.grid where export would fail if a search filter applied to a non-visible column
Design cleanup
Fixes issue1828
more docstring fixes
Merge pull request #367 from timrichardson/issues/1864

fixed a bug in SQLFORM.grid where export would fail if a search filter a...
Merge pull request #368 from nicozanf/patch-1

Design cleanup
Merge pull request #369 from spametki/issue1828

Fixes issue1828
Merge pull request #370 from niphlod/docs/refactor_c_d_f_g_h

more docstring fixes
fixed issue 1862, readline problem in cpdb, thanks  kmelevskiy
Step 1 in fixing 1859: this stops the crashing, but virtual fields are not exported
step 2 of fixing export from grids when there are virtual fields. Note export hidden columns includes all table fields and any virtual fields which are displayed, but it does not pick up virtual fields which are not displayed.
when exporting hidden columns, pick up all virtual fields, even those not on display.
fixed comment
Minor usability improvement to grid search widget
changed the button "New" to "Add" and added a title attribute (view on hover) explaining what this button does
Merge pull request #371 from timrichardson/issues/1859

Issues/1859 export from grid fails when virtual fields are present
Merge pull request #372 from timrichardson/search_widget_button_label_change

Minor usability improvement to grid search widget