3655 Fix further inconsistencies in help text

https://code.google.com/p/otwarchive/issues/detail?id=3655

in categories-help.html...

Was: Categories Tags
Is: Category Tags
Why: English

Was: Female/Female
Is: Female/Female relationships
Why: Because symbols-key.html used "relationships" and it sounded nicer

Was: Female/Male
Is: Female/Male relationships
Why: Because symbols-key.html used "relationships" and it sounded nicer

Was: General: no relationship, or containing relationships which are not the main focus of the work
Is: General: no romantic or sexual relationships, or relationships which are not the main focus of the work
Why: Because the symbols-key.html version was clearer about whether a Gen work can contain, say, friendships or parent-child relationships or...

Was: Any combination of relationships, multiple partners
Is: More than one kind of relationship, or a relationship with multiple partners
Why: To match symbols-key.html, but both versions were edited to get rid of the kinda unnecessarily awkward phrasing of "of the relationships listed here"

Was: Other
Is: Other relationships
Why: Because symbols-key.html used "relationships" and it sounded nicer

in symbols-key.html...
Was: General audiences
Is: General Audiences
Why: We capitalize all the words of our rating tags in most places they're displayed (e.g. filters, post new form, in the title text when you hover over the rating icon)

Was: Teen
Is: Teen And Up Audiences
Why: Because it's the full name of the tag

Was: Explicit, only suitable for adults
Is: Explicit: only suitable for adults
Why: Because we use colons instead of commas in the category section, and the document should have some internal consistency

Was: alt="Femslash"
Is: alt="F/F"
Why: Because the title text when you hover over the category icon and the span text that serves as our fallback both say "F/F"

Was: Femslash: female/female relationships
Is: F/F: female/female relationships
Why: We don't generally refer to F/F as "Femslash" in user-facing text, likely because it's kind of Western-media-fandom-centric (and not even always at that; "altfic" was the word in some Western media fandoms)

Was: alt="Het"
Is: alt="F/M"
Why: Because the title text when you hover over the category icon and the span text that serves as our fallback both say "F/M"

Was: Het: male/female relationships
Is: F/M: female/male relationships
Why: We don't generally refer to F/M as "Het" in user-facing text, and the second half needed to be switched because F stands for female and the M stands for male, not the other way around ;)

Was: Multi: more than one kind of the relationships listed here, or a relationship with multiple partners
Is: Multi: more than one kind of relationship, or a relationship with multiple partners
Why: Kinda unnecessarily awkward phrasing of "of the relationships listed here"

Was: alt="Slash"
Is: alt="M/M"
Why: Because the title text when you hover over the category icon and the span text that serves as our fallback both say "M/M"

Was: Slash: male/male relationships
Is: M/M: male/male relationships
Why: We don't generally refer to M/M as "Slash" in user-facing text, likely because it's kind of Western-media-fandom-centric