filter: Unpack FILTER in case the expression querie FORMAT only.

This had a side effect of resetting FILTER of records to PASS
even without -mx.
More tests for vcffilter
Reflect changes in bcf_hdr_get_hrec(), updated teset files
Fix header dependencies for bcftools source files

Move inclusion of version.h to main.c so that only main.o is rebuilt
when version.h changes (it's also included from version.c, used by
the plugins).  Remove vcfsom.c's bgzf.h inclusion, which isn't needed.
reheader: Complain if no option given
filter: Support for querying subfields of string INFO tags;

Support for querying all fields at once, e.g. DP4[*]<0.
Both features will likely break when combined with FORMAT
expressions, experimental.
Support for regular expressions in queries
filter: Bug fix in %AVG() calculation, resolves #74
reheader: Fix in .vcf.gz header parsing
reheader: Samples can now be given as "old new" pairs,

thus only the samples which need to be renamed can
be given.
view: add sample exclusion

- add sample exclusion with `^` prefix
- exit if samples not in header mentioned. error becomes warning if `--force-samples` option set
- add test for excluding samples
- include in documentation
Merge pull request #76 from mcshane/feature/view_exclude_samples

view: add sample exclusion
manpage: Minor fix, correct is "--genotype", not "--genotypes"
vcfindex: add shortcut options for TBI and CSI index creation

- to match the similar options in `samtools index`
- also added a few checks on the input options and file types
Merge pull request #78 from mcshane/feature/vcfindex_options

vcfindex: add shortcut options for TBI and CSI index creation
mcall: Two fixes in GP and GQ output

- Allow GP without GQ
- GP and GQ works for haploid samples as well
mcall: Fixed remaining issues from previous commit
filter: Bug fix in region initialization,

pass the string just initialized, not NULL
Remove unused source files
Clean *.dSYM in plugins subdirectory

These are always created (on OS X) due to -g (from $(CFLAGS)) being
given to the linker by the .c -> .so all-in-one rule.

Avoid using "rm -r" when it is unnecessary.