[trunk] name errors found by pylint

Hello,

I ran pylint on the trunk server code, and it found a few bugs (I've doubled checked them for false positives, and these seem genuine, unless openerp is doing weird things with the namespaces under the cover):

************* Module openerp.report.render.rml2txt.rml2txt
E0602:423,71:_rml_template.set_next_template: Undefined variable 'name'
************* Module openerp.report.render.rml2html.rml2html
E0602:323,71:_rml_template.set_next_template: Undefined variable 'name'
************* Module openerp.addons.base.module.wizard.base_module_scan
E0602: 41,19:base_module_scan.watch_dir: Undefined variable 'module_name_re'
************* Module openerp.addons.base.ir.ir_model_constraint
E0602: 41,18:ir_model_constraint._module_data_uninstall: Undefined variable 'except_orm'
E0602: 41,29:ir_model_constraint._module_data_uninstall: Undefined variable '_'
E0602: 41,54:ir_model_constraint._module_data_uninstall: Undefined variable '_'
************* Module openerp.addons.base.ir.ir_model_relation
E0602: 33,18:ir_model_relation._module_data_uninstall: Undefined variable 'except_orm'
E0602: 33,29:ir_model_relation._module_data_uninstall: Undefined variable '_'
E0602: 33,54:ir_model_relation._module_data_uninstall: Undefined variable '_'

The following one is probably a false positive, but I'm awkward in relying in a variable leaking from a genexp. Also in this code, you don't provide the user with the full list of modules which cannot be uninstalled because of the presence of module data, which means that the user will have to unselect them one by one, which makes for poor user XP, so it probably deserves being rewritten by filling up a list with models matching the faulty condition.

************* Module openerp.addons.base.ir.ir_model
E0602:158,104:ir_model.unlink: Undefined variable 'model'

The last one is a requirement for a cleanup of an outdated if __name__ == "__main__" section:

************* Module openerp.tools.amount_to_text_en
E0602:127,27: Undefined variable 'int_to_text'
E0602:129,27: Undefined variable 'int_to_text'
E0602:131,14: Undefined variable 'int_to_text'

For the record the command line that I used is:

PYTHONPATH=.:openerp -rn -iy -dE,W,R,C,F -eE0602 openerp