Add comments to setenv[.bat|.sh] files. Set Xms to same value as Xmx to avoid memory resizing. Avoid to set CATALINA_PID in setenv.sh if already done (as some impact on setup when using Linux distro provided startup script).
Merge pull request #2 from amottier/master

Update of setenv scripts to avoid CATALINA_PID overriding & Xms equal Xmx & adding comments