Replaces busy workers with running tasks on wq-status.
Fixes typo on -W, and shows tasks running rather than worker state.
kill is a shell built-in not in /bin
write pid to file.

Otherwise kill is never called
no reason for exec to remove files
keep track of sand_filter_master so that it can be killed in cleanup instead.

As opposed to the previous behavior of waiting for completion or timeout.
remove linker/ls which is created during prepare()
Cleanup test detritus.
Rename reinterpret -> normalize for clarity.
Use EIO which is clearer than Hadoop's EINTERNAL.
Correct documentation.
Move environment handling to C.

o This eliminates the need for alternate bootstrap scripts for
  parrot_run and chirp_server.

o Loading the libjvm.so and libhdfs.so shared libraries is simplified
  by searching under JAVA_HOME/HADOOP_HOME for these filenames and
  attempting to load indescriminately. If there is an architecture
  incompatibility (x86-32 vs. x86-64) causing dlopen to error, then we
  keep looking.

o CLASSPATH is now populated with all .jar files.
Simplify and correct Chirp tests.
Factorize out current_tasks_*command
Rewords help messages
Require explicit master for -T, -W
Merge pull request #223 from btovar/wq-status-show-number-of-tasks

1. Replaces busy workers with running tasks on wq-status. 
2. Some refactoring and cleanups. 
3. Require explicit master for -T, -W option in wq_status.
Fix segfault when wrapping category and condor
Correct -J default show_help for makeflow
Fix a bug where Parrot didn't check buffer size.

Fixes #235.
With Haiyan's help.