Use INTEGER for all integral types on SQLite.

From http://www.sqlite.org/datatype3.html it seems that SQLite does not
distinguish at all between the different types, so in general it does
not matter which one you use (and all the standard names are understood
by SQLite), except for Auto-Increment columns where you must specify
INTEGER as the type.
Merge pull request #909 from slick/tmp/sqlite-integer

Use INTEGER for all integral types on SQLite.
Remove misguided performance optimization from NominalType.

Putting the structural view into a second parameter list was done to
speed up equality and hash code computation for NominalType, on the
grounds that structural views have to be consistent anyway throughout
the tree. However, this invariant only holds between phases. Inside a
phase, the structural expansions may be temporarily inconsistent,
causing Node.nodeTypedOrCopy to overwrite a type that has already been
seen when replacing a NominalType with a new NominalType that has the
same TypeSymbol but a different expansion.

Fixes #912. Test in UnionTest.testBasic.
Merge pull request #913 from slick/tmp/issue-912

Remove misguided performance optimization from NominalType.
Merge pull request #924 from slick/tmp/2.1-rc2-changes-to-master

Merge 2.1.0-RC2 bug fixes into master
wip: Composable OptionParam

- Composes for all arities
- No more need for separate OptionMapper2 and OptionMapper3
- Much nicer error messages
- Easier to use than the OptionMapper DSL

The grunt work of converting all extension method trait still needs to
be done. I haven’t examined the effect on compiler performance, either.