rrc_cell_cfg: fix potential div by zero

similar fix has been applied for SR resources

cell_search_nbiot: show DL frequency in MHz

fixing bug in RRC measurement when receiving periodic config

in the UE conformance testing we've spotted an issue
where an event was evaluated even though the trigger type for
the report was periodic which caused an exception in RRC

SRSENB: Fixed PUCCH resource selection

bump version and update changelog, readme, etc.

adjust break and replace info in control file and adjust copyright

initialize and reset avg_noise in phch_common

update changelog for deb package

update changelog for 18.06.1

Update README.md