Sort out dependency on one particular version of comtypes
Created originally on Bitbucket by gstefanik (Gábor Stefanik)
According to the README, TortoiseHg's installer build requires a particular, modified version of comtypes installed on the system. This is probably fine for building official nightlies on dedicated build slaves, but not for 3rd parties trying to build their own testing or internal versions. If there is a dependency on a modified library, it should be packaged with or retrieved by the build system.