Memory Map XML for FLASH regions needs blocksize

GDB issued warnings when pinkySim returned memory-map XML which
contained FLASH regions since they were missing the blocksize
property.  I modified MemorySim.c to set this property to 1 and now
GDB is happy.
Add isGdbConnected() method to IComm

This method is currently forced to return TRUE in mockIComm and only
return TRUE in SocketIComm when accept() has previously been called to
return a GDB client socket or select() on the listening socket
indicates that there is an awaiting connection to be accepted.
Reduce GDB packet size to 16k from 64k

GDB issued a warning that it was truncating the maximum packet size
down to 16k anyway so it might as well be reduced in mri4sim.c

I also modified shouldInterruptRun() to only call
IComm_HasReceiveData() if GDB is already connected since there is no
need to stall in that API checking for a CTRL+C if a socket hasn't even
connected from GDB yet.
Add pinkySim application

Now builds a pinkySim application which actually pulls all of the
modules that I have been working on into an actual functional
application that can actually run and execute ARMv6-M samples.

The resulting application is called pinkySim and once built, will be
found in the root directory of the project.
Add first sample

The FileTest sample exercises several of the semihosting APIs such as
open, read, write, close, unlink, etc.

I also created a startup library which can be used by all samples. It
takes care of initializing the C/C++ runtime and providing the syscall
handlers required by newlib.  Most of these just delegate the calls
over to GDB via hard coded breakpoints in SemihostThunks.S.