Fixed the configuration file in order to work with the web builder

Signed-off-by: Nuccio Raciti <raciti.nuccio@gmail.com>
Changed FS registration mechanism

Now it's possible to have more than one instance of a given file
system. For example, one could use more that one ROM file system
in different physical locations (a possible configuration is
internal Flash and external serial memories). This mechanism is
currently implemented only in the device manager (devman.c),
actual instance implementation require per-FS support (to be
implemented later).
Added FS registration data as argument to all FS functions

All the functions that implement a FS receive the instance data
of the FS (given at registration time to dm_register) as their
last argument. ROMFS was changed to take advantage of this.
Changed the ROMFS terminator char

The ROMFS termination char is now 0xFF instead of 0x00 (in preparation
of WOFS).
shell: multiple fixes

1. the filename for 'recv <filename>' was not set correctly
2. error messages for 'cp' were not always correct
3. check for copy errors and issue a message accordingly
Added WOFS + other stuff

This should really be more than one commit, but I wrote everything in one
shot and I don't feel like arranging the changes logically into different
commits. So, these are the changes:

- added WOFS (Write Once File System). This is a writeable file system that
  exists in the MCU's internal Flash memory and allows files to be written,
  but only once, in a single shot. More details to follow.
- the platform interface has a new MCU flash access interface.
- added WOFS "reference implementations" for two CPUs: LM3S8962 and
  STM32F103RE. They are easily extendable to other CPUs in the same platform
  and can be taken as a model for other platforms.
- the ROMFS file layout in memory was slightly changed.
- the simulator (src/platform/sim) got a new function (lseek).
- shell: now each shell command receives its arguments in a C-main-style
  (argc, argv) pair. This was originally Marcelo's idea and it finally
  made it to the master (although this particular implementation is mine),
  after I got fed up with all the argument parsing in the shell functions.
- new shell command: wofmt ("formats" a WOFS, effectively clearing it).
- a couple of small fixes in the shell code
Fixed WOFS compilation on sim (Linux)
WOFS fix: at most one file opened in write mode

Due to the nature of WOFS, at most one file can be opened on WOFS
in write mode at any given time.
fixed check for remaining size on WOFS
renamed INTERNAL_FLASH_BLK_SIZE to INTERNAL_FLASH_UNIT_SIZE
fixed compilation when BUILD_WOFS is not defined
WOFS documentation, part I
WOFS documentation, part II + a small style change
WOFS documentation, last part + another style change
added board EK-LM3S9D92 from TI (LM3S9D92)
Use canonical Mizar32 web page URL
Bumped CPU frequency to 80MHz for LM3S9B92/LM3S9D92
Merge branch 'master' of github.com:elua/elua
LM3S platform changes

1. Flash configuration is described in a file named flash_conf.h.
   This helps keeping things less confusing with WOFS.
2. WOFS enabled for LM3S9D92
RO string bug fix

Fixed bug reported by Tim Van der Hulst:

-------------------------------------------------------------------------------
dofile('/mmc/test.lua') -- OK
require('test') -- Fail!!

-------------
/mmc
test.txt                       5 bytes
gprs.lua                       2910 bytes
util.lua                       385 bytes
test.lua                       385 bytes

Total on /mmc: 3685 bytes

-------------

Error: [string "xmodem"]:23: module 'test' not found:
        no field package.preload['test']
        no file '/mmc/test.lua;/mmc/test.lc;/rom/test.lua;/rom/test.lc'
        no file '/mmc/test.lc;/rom/test.lua;/rom/test.lc'
        no file '/rom/test.lua;/rom/test.lc'
        no file '/rom/test.lc'
-------------------------------------------------------------------------------

The problem was actually in the way read-only strings were created. If a read-only
string creation call specified a size which was different than the actual (C) size
of the string, the string didn't get null-terminated, which in turn led to some
interesting errors (like the one above).