Cleaned-up abbrev definition from "for", "if" etc.
Is is very annoying to be entered automatically:
for (;;) {
}
each time I want to use the word "for" in a comment...
To expand "for" etc. when I really want it, I just have to use
Yasnippet (TAB), so the abbrevs are not needed at all.
I completed some snippets to cover some missing snippets after
deleting abbrevs (such as "while" for cc-mode, etc.).