Merge pull request #4 from okinoshima/master

update manual
change log command to log statement
update to libzen 3b2bed6c7cf14ae3cce25a3bc1696abcb2da48e2
support try-catch(single catch block only)
update to libzen db2a04a866182a6d5c943bdd731249e078b59ad1
support multiple catch block
support MultipleException
disable top level raising exception
remove ModifiedJavaScriptSourceGenerator
update import env, but not working
update to libzen 3e6294471a3c88a2f803e2ea15514ffe2cb0312f
improve regex matching operator
add NullException
update to libzen b9a3fccc60e95a1141fbf91a293358883106fff0
add error message to DShellException
update manual