Merge pull request #237 from danielepantaleone/release-1.10

B3 database tables check (mysql only)
Merge pull request #238 from danielepantaleone/release-1.10

[STORAGE] switched from MySQLdb to pymysql
[STORAGE] allow use of python-mysql.connector

Debian Wheezy doesn't have pymysql package, but seems that all the
functionalities needed are into `python-mysql.connector`.

NOTE: I don't have updated these files (and probably we don't need to):
- `pip-requires.txt`
- `py2exe_builder/readme.txt`
- `tests/storage/test_DatabaseStorage.py`
Forgot about unmatched 'try'
Merge pull request #239 from Ansa89/release-1.10-wheezy_fix

[STORAGE] allow use of python-mysql.connector