Since unistd.h is loaded by default, remove the redundancy.
A response to Change 120982:
> by dalexander on 2013/03/12 08:17:43
> Commit Mark's compile-fix patch
> [Tracking bug 22690]

[git-p4: depot-paths = "//depot/software/assembly/cpp/": change = 120990]
   bug 18909
   prop:S2.0
   Update blasr documentation:
       Remove -advanceHalf, -indelRate, -maxExpand.
       Add -affineExtend, -maxMatch.
       Correct the default value of sdpTupleSize.

[git-p4: depot-paths = "//depot/software/assembly/cpp/": change = 121192]
   bug 22806
   prop:S2.0
   Add an option -maxMemory to loadPulses so that one can set an approximated
   limit on loadPulses' memory consumption with -bymetric. The default limit is 6GB.
   LoadPulses will switch to -byread if the predicted memory consumption using
   -bymetric exceeds the limit.

[git-p4: depot-paths = "//depot/software/assembly/cpp/": change = 121250]
   bug 22806
   prop:S2.0
   Change the default memory limit for -bymetric from 6 GB to 4 GB.

[git-p4: depot-paths = "//depot/software/assembly/cpp/": change = 121253]
   bug 18909
   Fix coverity bugs

[git-p4: depot-paths = "//depot/software/assembly/cpp/": change = 122361]
bug 23004
   samtom4 - Add a new executable which converts a SAM file produced by 
             blasr to m4 format.
   samtom4 - Add a cram test for samtom4.
   blasr   - M4 printer: Fix a bug which occasionally prints incorrect 
             start/end coordinates in M4 (interval alignment printer) format,
   blasr   - M4 printer: Remove fields (including ncells, clusterScore, 
             probscore and numSigClusters) from -m 4 output.
   blasr   - SAM printer: Add an end-user tag 'xq' which stores the original
             PacBio read length.

[git-p4: depot-paths = "//depot/software/assembly/cpp/": change = 122362]
   bug 23080
Remove tailing tabs from blasr sam output.

[git-p4: depot-paths = "//depot/software/assembly/cpp/": change = 122566]