Renaming the reStructuredText files as .rst

--HG--
rename : README.txt => README.rst
rename : docs/groupserver-install.txt => docs/groupserver-install.rst
rename : docs/groupserver-start.txt => docs/groupserver-start.rst
rename : docs/index.txt => docs/index.rst
rename : docs/postfix-configure.txt => docs/postfix-configure.rst
rename : docs/proxy-configure.txt => docs/proxy-configure.rst
rename : docs/release-notes-1009.txt => docs/release-notes-1009.rst
rename : docs/release-notes-1010.txt => docs/release-notes-1010.rst
rename : docs/release-notes-1011.txt => docs/release-notes-1011.rst
rename : docs/release-notes-1012.txt => docs/release-notes-1012.rst
rename : docs/release-notes-1101.txt => docs/release-notes-1101.rst
rename : docs/release-notes-1102.txt => docs/release-notes-1102.rst
rename : docs/release-notes-1103.txt => docs/release-notes-1103.rst
rename : docs/release-notes-1104.txt => docs/release-notes-1104.rst
rename : docs/release-notes-1105.txt => docs/release-notes-1105.rst
rename : docs/release-notes-1106.txt => docs/release-notes-1106.rst
rename : docs/release-notes-1107.txt => docs/release-notes-1107.rst
rename : docs/release-notes-1108.txt => docs/release-notes-1108.rst
rename : docs/release-notes-1205.txt => docs/release-notes-1205.rst
rename : docs/release-notes-1211.txt => docs/release-notes-1211.rst
rename : docs/release-notes-1403.txt => docs/release-notes-1403.rst
rename : docs/release-notes-1406.txt => docs/release-notes-1406.rst
rename : docs/release-notes.txt => docs/release-notes.rst