The Grim Reaper calls. Take in the commit bits for the following
people who have neither made a src commit for at least 18 months, nor
have they responded to multiple emails about their status as
committers. This is clearing up a backlog of about 3 years where the
grim reaper process has not been happening.

agc Alistair Crooks
akiyama Shunsuke Akiyama
andre Andre Oppermann
charnier Philippe Charnier
cherry Cherry Mathew
das David Schultz
davidch David Christensen
edavis Eric Davis
fjoe Max Khon
iwasaki Mitsuru IWASAKI
kuriyama Jun Kuriyama
monthadar Monthadar Jaberi
ps Paul Saab
rnoland Robert Noland
sanpei MIHIRA Yoshiro
simon Simon Nielsen
stefanf Stefan Farfeleder
syuu Takuya ASADA
torek Chris Torek
venkat Venkat Duvvuru

Core would like to thank all of these people for their contributions
to the project, and wishes them well in any future endeavours.

While here, tidy up the mentors file. In addition to certain of the
above who were still technically under mentorship, remove entries for
carl, miwi and snb who had previously given up their commit bits.

Approved by: core (implicit)