version 1.6.0

See
http://forums.radioreference.com/digital-voice-decoding-software/256111-
dsd-1-6-closed-fork-open-source.html#post1884783
new options to control filters and P25 encrypted signals

I have added the -l and -pu options.
Merge commit '20271c6df57dacbaed3f2255a8230f44f58bd3ae'

Apparently when 1.6.0 was release it was not properly merged. This re-add the disable p25 encryption muting flag.

Conflicts:
	README
	dsd.h
	dsd_main.c
	dsd_symbol.c
	p25p1_ldu1.c
	p25p1_ldu2.c
Change current work to v1.7.0-dev
Add git tag / SHA1 as a build string

Every build from commit 20271c6 (Apr 10 2013) is versioned as 1.6.0.
Add a build version after the version number
Digital Speech Decoder 1.6.0 (build:v1.6.0-20-g16110bd)

The build string uses git describe to list the tag closest to head,
and the number of commits past that tag, the a litteral g and ending
with the current SHA1
Merge pull request #15 from dreinhold/add_git_sha_version

Add git tag / SHA1 as a build string
Added decoding and error correction on the NID fields: NAC and DUID. Making use of the IT++ library for BCH encoding/decoding.
Parity errors in NIC are now ignored.
Clean up the code to make it easier to understand. Now the logic to error correct the NIC makes more sense.
Merge pull request #20 from EdFuentetaja/master

Added decoding and error correction on the NID fields: NAC and DUID.
Add itpp as a requirement in readme
Added support for error correction in P25 HDU data.
Both Golay(24,12,8) and Reed-Solomon(63,47,17) are now implemented.
Merge pull request #22 from EdFuentetaja/master

Added support for error correction in P25 HDU data.
Use gtest for golay24 and reed-solomon tests
Update samples
Added a few comments, fixed ortography and some other cosmetic changes.
Merge branch 'master' of https://github.com/szechyjs/dsd.git
Added error correction to the metadata of LDU1 and LDU2.
Refactored implementation of p25p1_ldu1.c and p25p1_ldu2.c. There are less duplicities now and hopefully is easier to read and maintain.
Added a unit test for the Hamming algorithm.
Move bulk of README to the Wiki
Merge pull request #23 from EdFuentetaja/master

Error correction on the metadata fields of P25 LDU1 and LDU2
Fix compile errors from #23