update URLs in README.md
Added tag 2.11 for changeset 9678f86d3f6f
add default namespaces also in XPath expressions containing "and" or "or"
improve word order in README.md
sort options in usage list in README.md
Added tag 2.10 for changeset 1ae5775b4eab
add option "-s" ("--spaces")
add options "-p" ("--pis") and "-P" ("--comments")
simplify argument parser
remove whitespace in shebang
fix link to COPYING in README.md
change color of ellipsis in abbreviations
Added tag 2.9 for changeset 254dec1347bf
add option "-a" ("--abbreviate")
Added tag 2.8 for changeset feeb9e97dbc3
add option "-M" ("--files-and-matches")
update README.md