Merge pull request #113 from gordon/windows

Windows: single script to build gt-distributions
reduce travis runs
output while tests run

closes #89
Merge pull request #114 from Garonenur/travis

Travis
add const char* gt_version(void) to API
put gt_fasta_show_entry() into FASTA module

fixes a documentation problem
GFF3 output with "retainids": multi-features

Make sure the GFF3 output of multi-features with "retainids" is always correct
and does not depend on the position of the representative. This fixes #115.
Merge pull request #117 from gordon/multifeature

GFF3 output with "retainids": multi-features
use tab
Merge pull request #116 from gordon/version

add gt_version() and fix documentation problem
use GT_PATH_SEPARATOR and GT_PATH_VAR_SEPARATOR

where necessary
define paths correctly for Windows
coding style
Windows: fopen() fails for directories

define and use gt_file_exists_and_is_dir()
Windows: fix basename unit tests
escape PATH variable