set memory in CATALINA_OPTS in init file

This commit allows for setting Xms, Xmx and permgen in init file via
export of CATALINA_OPTS. The settings can be changed via the jira class
as described in the README
update setenv to properly set JVM memory changes

this commit includes a modified version of the setenv.sh file, in the
original file the options for JVM memory are overrided so we can't set
it properly in the manifests.
change name from initial_memory to minimum_memory
add setenv.sh in spec
fix wraps in setenv.sh
set JVM options on class jira

this commit allows the user to set JVM options when calling the class
jira, the usage is documented in example in README.

The setting will be added to the command when running the JVM in
setenv.sh so when using several commands it has to be separated by a
space and the flag to be used.
Merge pull request #1 from antonlindstrom/allow_setting_memory_allocation

Allow setting memory allocation