Startup script needs more LSB compatability

The zkServer.sh script kind of sort of implements the standard init.d style of interaction.

It lacks

• nice return codes

• status method

• standard output messages

See

http://refspecs.freestandards.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html

and

http://refspecs.freestandards.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptfunc.html

and

http://wiki.debian.org/LSBInitScripts

It is an open question how much zkServer should use these LSB scripts because that may impair portability. I
think it should produce similar messages, however, and should return standardized error codes. If lsb functions
are available, I think that they should be used so that ZK works as a first class citizen.

I will produce a proposed patch.