add common GNU dependencies

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>
add RCS

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>
add SQLite

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>
add libungif

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>
fix remarks, add Tcl dep for SQlite
Merge pull request #347 from boegel/contrib_GNU_common_deps

contribute common GNU deps