Handle double quotes and spaces to fix parsing of lines with multiple…

[DaleStan]

… equals signs.

My savegames have several lines with multiple equals signs, usually in a special interest block:

special_interests=
{
	2601095="antagonizing_target_key" 2630399="swaying_target_key" 
}

or an artifact history block:

history=
{
	2605626=779.5.22 2657349=787.6.3 
}

This PR changes the tokenization of those lines so the parser can convert them to json.

It also changes the tokenization of att= and tr= lines. As far as I can tell, the resulting json for those lines is identical, so this does not turn into a breaking change.