FIX: ELF: rename word used for imported symbols for clarity
FIX: ELF: rename word used for imported symbols for clarity

Renamed from 'symbols' to 'imports', to prepare for also supporting
exported symbols.

rheber/red,red-eco/red,NikolayShubenkovProgSchool/red,vehar/red,rheber/red,red-eco/red,iArnold/red,vehar/red,iArnold/red,NikolayShubenkovProgSchool/red