Mode added to BusIn + allow creation of NC pins

Now BusIn can also use PullUp, etc, instead of only BusInOut.

If the pin is NC, it does get to the init, but all write/mode functions
are disabled. This is how it used to be in the old gpio version. Quite
some libraries allow users to make pins NC, and they are all locking up
with the current mbed version. This is far from a perfect solution, but
more a temporary fix.
Added NET_1 and NET_2 (TCP / UDP client) automated tests to test suite
Added new functionality: now you can use -P switch to test MUT's peripherals only
Added 'ethernet' peripheral dependency to all NET_x tests
Added EXAMPLE_1 /dev/null redirection host test to automation suite
Added 75% treshhold for test groups progress bars. In -r option
Small testing script refactoring
[NUCLEO_F302R8] Implement analogout_free function

This code was missing + make some typo corrections.
[DISCO_F407VG] Fixed PWM PA_3 (and PC_9) output issue.
Refer to:
http://mbed.org/users/mbed_official/code/mbed-src/issues/4
Merge branch 'master' of https://github.com/mbedmicro/mbed
[NUCLEO_F302R8] Implement analogout_free function

This code was missing + make some typo corrections.
Merge pull request #261 from dinau/pwm_pa3_issue

[DISCO_F407VG] Fixed PWM PA_3 (and PC_9) output issue.
Merge pull request #247 from Sissors/master

Mode added to BusIn + allow creation of NC pins
Initial K20 fixes

Added the required gpio-irq enable/disable + fixed bus_frequency
Added NET_13 TCP client echo loop host test to test automation suite
Bug fix, crash when using both -v and -P flags - reported by Mihail
Added proper host test script for NET_13 test
Small updates for NET_7 HTTP Client test
Automation listing refactoring
Added KL25Z_5 MMA8451Q accelerometer test to test automation suite