#8 Allow "and" of attribute test predicates

[Eamonn O'Brien-Strain]

(Requested by Denis Bohm.)

Currently the subset of the XPath language limits you
to one attribute test per step. We would like to
extend this to allow at least boolean anding of
attribute tests. We could extend the subset in one of
two ways to get this:

(1) Allow multiple predicates per step:

/a/b/c[@foo='ppp'][@bar='qqq']

(2) Allow boolean expressions in a predicate

/a/b/c[@foo='ppp' and @bar='qqq']