1. Removed globaly initialized data inside class test() function
2. Removed global variables initialization dependency. Any cause some Python
   implementations and configurations to fail in runtime
3. Added info about Echo port #7 rationale.
4. Testsed with K64F and network tests:

Test summary:
+--------+--------+---------+----------------------------+--------------------+
| Result | Target | Test ID | Test Description           | Elapsed Time (sec) |
+--------+--------+---------+----------------------------+--------------------+
| OK     | K64F   | NET_1   | TCP client hello world     |        3.26        |
| OK     | K64F   | NET_13  | TCP client echo loop       |        2.05        |
| OK     | K64F   | NET_2   | NIST Internet Time Service |        3.43        |
| OK     | K64F   | NET_3   | TCP echo server            |        1.54        |
| OK     | K64F   | NET_4   | TCP echo client            |        1.54        |
| OK     | K64F   | NET_5   | UDP echo server            |        1.46        |
| OK     | K64F   | NET_6   | UDP echo client            |        1.6         |
| OK     | K64F   | NET_7   | HTTP client hello world    |        3.4         |
| OK     | K64F   | NET_8   | NTP client                 |        2.39        |
+--------+--------+---------+----------------------------+--------------------+
Result: 9 OK

Completed in 122.18 sec