Change parsing error message to mention -INF

[pjfanning]

-INF is allowed.

The code is unclear about whether 'INF' is allowed. '+INF' seems to be tested and seems to work but 'INF' seems to be documented but I'm not sure if it works.

[cowtowncoder]

That sounds reasonable if correct; but let me try to have a look first... definitely needs to include -INF

[cowtowncoder]

Hmmmh. So, tests in com.fasterxml.jackson.core.read.NonStandardParserFeaturesTest check for content:

        final String JSON = "[ -INF, +INF, +Infinity, Infinity, -Infinity ]";

which does NOT include INF but does full versions. ReaderBasedJsonParser appears to (maybe?) accept it.
Test mentioned above does fail on INF for what that is worth.

So I think I'll go with this.