Impose stricter control on requested URI on both server and client side

These patches fix Issue#70. All kinds of tests passed successfully:

1. no Valgrind leakage detected on both sides;

2.
[harry@ndclin004 scripts.bk]$ curl -XPOST --data '' http://localhost/obix/watchService/0/watch1//delete
<?xml version="1.0"?>
<err is="obix:UnsupportedErr" name="General error contract" displayName="oBIX Server" display="Invalid URI"/>
[harry@ndclin004 scripts.bk]$ 

3.
[harry@ndclin004 scripts.bk]$ curl localhost//obix
<?xml version="1.0"?>
<err is="obix:UnsupportedErr" name="General error contract" displayName="oBIX Server" display="Invalid URI"/>
[harry@ndclin004 scripts.bk]$ 

4.
[harry@ndclin004 obix]$ make test
Running tests...
Test project /work/obix
      Start  1: Dependencies
 1/17 Test  #1: Dependencies .....................   Passed    0.05 sec
      Start  2: Setup
 2/17 Test  #2: Setup ............................   Passed    0.01 sec
      Start  3: Server_Start
 3/17 Test  #3: Server_Start .....................   Passed    0.01 sec
      Start  4: test_watch_delete.test
 4/17 Test  #4: test_watch_delete.test ...........   Passed    0.38 sec
      Start  5: test_uri_read.test
 5/17 Test  #5: test_uri_read.test ...............   Passed    0.52 sec
      Start  6: test_uri_write.test
 6/17 Test  #6: test_uri_write.test ..............   Passed    0.52 sec
      Start  7: test_device_lobby_exists.test
 7/17 Test  #7: test_device_lobby_exists.test ....   Passed    0.03 sec
      Start  8: test_signup_exists.test
 8/17 Test  #8: test_signup_exists.test ..........   Passed    0.18 sec
      Start  9: test_uri_write_invalid.test
 9/17 Test  #9: test_uri_write_invalid.test ......   Passed    0.52 sec
      Start 10: test_watch_exists.test
10/17 Test #10: test_watch_exists.test ...........   Passed    0.17 sec
      Start 11: test_device_signup.test
11/17 Test #11: test_device_signup.test ..........   Passed    0.35 sec
      Start 12: test_batch_exists.test
12/17 Test #12: test_batch_exists.test ...........   Passed    0.03 sec
      Start 13: test_issue_69.test
13/17 Test #13: test_issue_69.test ...............   Passed    0.17 sec
      Start 14: test_history_exists.test
14/17 Test #14: test_history_exists.test .........   Passed    0.18 sec
      Start 15: test_watch_make.test
15/17 Test #15: test_watch_make.test .............   Passed    0.20 sec
      Start 16: test_obix_features.test
16/17 Test #16: test_obix_features.test ..........   Passed    0.17 sec
      Start 17: Server_Stop
17/17 Test #17: Server_Stop ......................   Passed    0.03 sec

100% tests passed, 0 tests failed out of 17

Total Test time (real) =   3.53 sec
[harry@ndclin004 obix]$