new LagrangePolySpace._eval_base(), update derived classes
new LagrangePolySpace._eval_base(), update derived classes

- update LagrangeSimplexPolySpace:
  - update .__init__() - new init_context argument
  - remove ._eval_base()
- update LagrangeSimplexBPolySpace:
  - update .__init__() - new init_context argument
  - update .create_context() - support **kwargs
  - remove ._eval_base()
- update LagrangeTensorProductPolySpace:
  - update .__init__() - new init_context argument
  - remove ._eval_base()

BubuLK/sfepy,sfepy/sfepy,rc/sfepy,sfepy/sfepy,RexFuzzle/sfepy,rc/sfepy,RexFuzzle/sfepy,RexFuzzle/sfepy,vlukes/sfepy,lokik/sfepy,BubuLK/sfepy,sfepy/sfepy,rc/sfepy,vlukes/sfepy,lokik/sfepy,vlukes/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,lokik/sfepy,lokik/sfepy