[WIP] clang - attempt to reenable boolean vectors

[timkpaine]

This PR builds on #83 and attempts to reenable vector<bool> by targeted specialization of functions that would've resulted in bit references.

It fails the same tests as #83 , but is probably closer to the end solution. The failing tests are almost all pandas related

FAILED csp/tests/impl/test_dateframe.py::TestCspDataFrame::test_math_ops - AssertionError: False is not true
FAILED csp/tests/impl/test_pandas_ext_type.py::TestBooleanReduce::test_reduce_series_boolean[all-True] - AssertionError: Input are different
FAILED csp/tests/impl/test_pandas_ext_type.py::TestBooleanReduce::test_reduce_series_boolean[all-False] - AssertionError: Input are different
FAILED csp/tests/impl/test_pandas_ext_type.py::TestBooleanReduce::test_reduce_series_boolean[any-True] - AssertionError: Input are different
FAILED csp/tests/impl/test_pandas_ext_type.py::TestBooleanReduce::test_reduce_series_boolean[any-False] - AssertionError: Input are different
FAILED csp/tests/impl/test_pandas_perspective.py::TestCspPerspectiveTable::test_run_types - AssertionError: Series are different
FAILED csp/tests/test_history.py::TestHistory::test_range_access - AssertionError: dtype('int8') != dtype('bool')
FAILED csp/tests/test_type_checking.py::TestTypeChecking::test_runtime_type_check - AssertionError: TypeError not raised

[timkpaine]

i have a third approach using a proxy for a bool type with implicit conversions