debian/mozclient: remove old makefiles

The various content of debian/mozclient/* is now integrated directly
into debian/rules. The non Debian spedific branding part isn't also not
needed any longer as Ubuntu doesn't use the work of Debian any more.
debian/rules: adding override for dh_strip

Without the additional argument for dh_strip the icedove-dbg package
isn't builded.
debian/control: remove ${shlibs:Depends} from c-g-p depends

dpkg-gencontrol remains a unknown substitution variable
${shlibs:Depends} for the calendar-google-provider package. It's not
needed so remove the Depends list.
debian/rules: adding additional LDFLAGS
debian/rules: correcting Icedove version inside icedove.pc while install
remove this file, it's confusing git-pbuilder

   !!!! Do not pick this commit !!!!
libinotify: re enabling notification of new mails

The ability of notification about new mails was removed by Mozilla
between version 17 and version 24. Thanks to Ubuntu this functionality
is available again.