remove bool conversion

as discussed in noplay/python-mysql-replication#16
Merge pull request #65 from lxyu/master

remove bool conversion
add primary col info
primary_key now can be either str or tuple

in favor of sqlalchemy's primary_key definition style
Merge pull request #66 from lxyu/primay_col_info

expose primay_keys info for row based events
Useless statement

I may be wrong, but that declaration seems to be absolutely worthless.

Also added PyCharm files to the ignore.
Merge pull request #70 from mafagafo/master

Useless statement
Deletion of repeated entries (double declaration)
Merge pull request #71 from mafagafo/master

Deletion of repeated entries (double declaration)
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