out-xpath: support namespace prefixes defined in the input document

cli: utility option --reader-namespace-aware (shortcut for "http://xml.org/sax/features/namespaces" feature)

cli, lib-input: propagate features and properties to parser/reader

cli: parse reader features option

out-xpath: optional variable resolver for environment variables – can be used together with those from command line

analýza: odkazy na zdroje k INI souborům

in-ini: comments

in-ini: regex clean-up

in-ini: re-eble whitespace in entry keys – but trim spaces before „=“ to support:
„ a b c = d“ → „<a-b-c>…“ instead of „<a-b-c->…“

in-ini: support sub-keys:
key[subkey_1]=value_1
key[subkey_2]=value_2