refs #4843 Added option to read log file

There is now a tickbox in the C2E GUI which allows users to select whether or not to simultaneously load the log file associated with the raw file they wish to load.
refs #4843 Changes from the develop branch

Code on develop branch was more up-to-date. This prevents merge conflict and also includes changes which gives users to load logs.
refs #4843 Changes to labelling
refs #4843 Solves merge conflict
refs #4843 Removed unnecessary comment.
Merge branch 'master' of github.com:mantidproject/mantid
Merge branch 'master' of github.com:mantidproject/mantid
refs #4843 Solved potential merge conflict
Merge branch 'master' of github.com:mantidproject/mantid
Merge branch 'master' into feature/4843_load_logs
Merge remote-tracking branch 'origin/feature/4843_load_logs'