Fix typos

Found via `codespell -q 3 -S "*.pdf,*.po,*.pot,*.pgm,./flowblade-trunk/docs/RELEASE_NOTES.md,./flowblade-trunk/Flowblade/locale/iso_locales,./flowblade-trunk/Flowblade/res/css3/sass/test.css.map" -L atleast,eacf,indx,ist,ody,persistance,trough`