Cryptocat 2.0.42

- IMPORTANT: Due to changes to multiparty key generation (in order to
be compatible with the upcoming mobile apps), this version of Cryptocat
cannot have multiparty conversations with previous versions. However
private conversations still work. Due to this, this release will not be
pushed until it is both reviewed by Mozilla (for the Firefox Addons
Website) and Apple (for the Mac App Store).
- Fixed a bug found in the encryption libraries that could partially
weaken the security of multiparty Cryptocat messages.