#20 functions removed from XPath2

[Petr Cimprich]

Some functions reused by STX were droped in XQ1XP2 WD
12 Nov 03. We need to decide if they stay in STX or
not. Still in the STX spec (WD 9 Dec 03) now.

node-kind()

string-pad()
the removal would require the FOR loop

item-at()
the removal wold require predicates for sequences: $seq[1]