Various small fix

[un-pogaz]

Three various small fix

1. Add & operator and $ prefix to their doc function
2. Remove space in some functions arguments
3. Fix various unquoted arguments

[kovidgoyal]

@cbhaley please review

[cbhaley]

These are all good changes with one exception. That exception: in the commit "add & operator and $ prefix doc" the addition in the second hunk, "The $ prefix can be used instead of the function, as in $tags." is incorrect. The function returns the count of items in a multi-valued field. $field returns the field itself.

[un-pogaz]

Hum... crap. I miss the good function to that, I push the fix.

[cbhaley]

All good now.