Make keywords and control structures in log look more like original data

[pekkaklarck]

Currently keywords and control structures are formatted differently in the log file than they look in the data. For example, you have a keyword call like

Log Many    a    b    c

and a FOR loop like

FOR    ${x}    IN    cat    dog    horse

in the data, they look like

KEYWORD  BuiltIn.Log Many a, b, c

and

FOR  ${x} IN [ cat | dog | horse ]

in the log file.

I believe this should be changed. Most importantly, we should use the normal four space separator between items and omit all markers that wouldn't be supported in the data. The above examples could look like

KEYWORD  BuiltIn.Log Many    a    b    c

and

FOR    ${x}    IN    cat    dog    horse