Removed calls to updateEnvironmentVariables() in the
addEnvironmentVariables(String,IEnvironmentVariable),
addEnvironmentVariables(Map<String,IEnvironment>)and
removeEnvironmentVariable(String)
Resolves #1
Removed call to updateEnvironmentVariables() from
EnvironmentVariableResource.
Resolves #2
Updated tests to reflect requirement of users of
IEnvironmentVariable.destroy() to refresh their own instances of
IApplication, when not working from within an IApplication
implementation instance. Also added remove method that takes an instance
of IEnvironmentVariable as explicit parameter, to IApplication and
ApplicationResource.  Also added instantiation of
environmentVariablesMap within ApplicationResource, and made requisite
changes to getOrLoadEnvironmentVariables(), and
updateEnvironmentVariables() Resolves #3, resolves #6, resolves # 9