Returns whether a socket is eligible for the glyph currently awaiting a target.
Only valid during glyph application: when the player has activated the glyph item but before she has chosen the glyph slot to put it in (i.e. the glowing hand cursor is showing).
See also Glyph functions.
socket- Which glyph socket to query (between 1 and
match- 1 if the glyph awaiting a target fits the given socket; nil if it doesn't fit or if no glyph is awaiting a target (