som: strict separation of evaluation and training data
filter,subset: Support for unary minus in filter expressions
stats: If RC stats not requested, count all indels as "others"
som: New default is -f5
subset,filter: Support for querying Flag types
Update travis
subse,filter: Fix for INFO strings not terminated by \0
Fixed warnings given by gcc version 4.6.3
Add "make install" target
vcfsom: Check fread status
Updated travis file to make bgzip and tabix available for testing
Updated travis file: will it work now?
test.pl now returns proper status when some of the tests fails
Added $(PROG) dependency to the "test" rule
Updated documentation + do not print full path in version string
filter,subset: Support for doubles with exponents; More strict parsing of numeric expressions
som: Do not loop endlessly with -f1; fix initialization of get_max_score
filter,subset: more terse parsing of doubles
Remove unused recursive Makefile infrastructure

With SUBDIRS=. there is no need for this *-recur infrastructure.
Moreover with bcftools depending on a phony target, it was needlessly
rebuilt every time, which led to "make install" rebuilding it -- which
is a problem if for example you are building and installing on different
machines/distros/architectures.

Also remove versioning complexity needed by htslib's Makefile but
unneeded here as we're not building a library.
Input file type now detected automatically, removed the now unnecessary options