D 1.076 and 2.061 release

[bearophile]

Are you going to remove the D1 compiler parts of code in the D2
compiler source code? A leaner source base will help.

Also this transitional moment seems a good moment to rename the
".c" suffix of the frontend+backend C++ files to ".cpp" or
something like that.


I have to warn people that if they want to suddenly switch from
2.060 to 2.061 with no intermediate steps, probably some of their
code will break, and they will have to work to fix it.

Bye,
bearophile