Deprecate envvar OSMO_GSM_TESTER_CONF and remove other ones

Environment variable OSMO_GSM_TESTER_CONF is marked as deprecated and an
error is logged each time it's used. Same feature is available through
"-c" command line parameters, so having the envvar only makes things
more complex for no good reason. It cannot yet be completely dropped
since some environemnt still make use of it. Give some time to users to
adapt their setups.
Other environment variables setting some config apths can be dropped
since they are not being really used in any setup.

Change-Id: I7eb69f870d0dcb5906d45ae067d6bed1aabf5862
diff --git a/src/osmo-gsm-tester.py b/src/osmo-gsm-tester.py
index 7bd2fd6..84151b8 100755
--- a/src/osmo-gsm-tester.py
+++ b/src/osmo-gsm-tester.py
@@ -23,9 +23,9 @@
 
 Examples:
 
-./run_once.py ~/my_trial_package/ -s osmo_trx
-./run_once.py ~/my_trial_package/ -c sms_tests:dyn_ts+eu_band+bts_sysmo
-./run_once.py ~/my_trial_package/ -c sms_tests/mo_mt_sms:bts_trx
+./osmo-gsm-tester.py -c doc/examples/2g_osmocom/ ~/my_trial_package/ -s osmo_trx
+./osmo-gsm-tester.py -c doc/examples/2g_osmocom/ ~/my_trial_package/ -s sms_tests:dyn_ts+eu_band+bts_sysmo
+./osmo-gsm-tester.py -c sysmocom/ ~/my_trial_package/ -s sms_tests/mo_mt_sms:bts_trx
 
 (The names for test suite, scenario and series names used in these examples
 must be defined by the osmo-gsm-tester configuration.)
@@ -124,8 +124,7 @@
     parser.add_argument('-R', '--source', dest='source', action='store_true',
             help='Enable stdout logging of source file')
     parser.add_argument('-c', '--conf-dir', dest='conf_dir',
-            help='''Specify configuration dir (overrides
-OSMO_GSM_TESTER_CONF env and default locations)''')
+            help='''Specify configuration directory path (containing paths.conf)''')
     args = parser.parse_args()
 
     if args.version: