Feature/435 loglib refactoring

### Description
The log library and its usage in contextBroker.cpp has been modified to allow for transaction ids in each log line.
Also the name of the log file has been changed, and many many log lines have been modified to be more coherent.

This PR solves issue #435.

I will restructure the part about loging with a bullet for all the log stuff (referrint to issue #435) and the different specific actions as subpoints, e.g:

```
o Logging re-writting (isseu #428):
   o Changing the log line format to use a key-value approach
   o Changing the time reference to localtime (previously they use GMT)
   o The name of the log file has been changed from contextBrokerLog to contextBroker.log
   o Removing -v, -vv, -vvv, -vvvv, -vvvvv
```
Maybe I'm missing some sub-point...