removeExtraSpacesLF removes extra spaces and selected carriage returns from input string
newTxt=removeExtraSpacesLF(txt)
exampleGiven an input string possibly containing a series of carriage returns (CR) and white spaces, removeExtraSpacesLF removes all carriage returns except those when: 1) symbol ';' is followed by one or more spaces and a CR;
2) symbol ':' is followed by one or more spaces and a CR;
3) symbol '.' is followed by one or more spaces and a CR;
4) symbol '
\[' is followed by one or more spaces and a CR; 5) symbol '\]' is preceded by one or more spaces and a CR.
6) symbol '\\' is preceded by one or more spaces and a CR.