[3.7] Syntax error when importing pydle; caused by a module called "async"

[selplacei]

Since async was added as a keyword in Python 3.7, importing async.py as a module raises a syntax error. I resolved this by simply renaming the module to something else and editing pydle's source files accordingly. As of now, the library is unusable on 3.7 until the user renames that file.

[Harmon758]

Duplicate of #76

[shizmob]

Fixed with the most recent merge, release pending!