`icontains`, `istartswith`, `iendswith`

[jvanasco]

discussed previously in * https://groups.google.com/forum/#!searchin/sqlalchemy/icontains/sqlalchemy/MUyt8zYaP0c/ht4fGR9q9w8J * https://groups.google.com/forum/#!searchin/sqlalchemy/icontains/sqlalchemy/331XoToT4lk/RPjIYNTkSEIJ

I tried doing this myself, but don't know enough of the internals to get this done on my own.

it looks like these need to be modified

• sqlalchemy/sql/default_comparator.py
• sqlalchemy/sql/operators.py

but not sure about

• sqlalchemy/sql/compiler.py

there are probably more files.

if someone can get one working, I can do the rest and build out tests.