making alternate allele frequency work in the case of non-diploid alleles
fixing small typo in elif in test case for aaf
adding one more test case for non-diploids
updating ploidy vcf example file
Adds _Record.affected_start and .affected_end.

These coordinates should represent the zero-based, half-open region of
the reference sequence affected by all the events included in ALT. These
coordinates allow the user to identify precisely which bases are altered
by the events in the record.

Provides more thorough documentation on the coordinate schemes for
_Record.POS, .start, and .end.
Merge pull request #161 from gotgenes/feature-affected_coordinates

Adds _Record.affected_start and .affected_end.
Merge pull request #148 from mgymrek/master

making alternate allele frequency work in the case of non-diploid genotypes
Allow flag INFO field to be declared as string

As reported in #164, we previously crashed on flag INFO fields declared
as strings (and the number of values declared as 1). This is indeed not
according to spec, but we should probably allow it anyway.
Don't crash when FORMAT is set to the missing value (.)

It is not valid according to the spec, but issue #164 shows a VCF file
where the FORMAT column contains just a dot character. We have no way
of interpreting the subsequent genotype columns in that case, so this
patch ignores them.
Merge pull request #165 from martijnvermaat/string_as_flag

Allow flag INFO field to be declared as string
Merge pull request #166 from martijnvermaat/format-none

Don't crash when FORMAT is set to the missing value (.)
Don't crash on metadata lines without value

The spec actually does not allow for metadata lines without value, but we
shouldn't crash on them.

Fixes #168