added transform functionality for raw_contig <-> slice and slice <-> slice (transform() and _transfrom_XXX())
added transform functionality
for raw_contig <-> slice and slice <-> slice
(transform() and _transfrom_XXX())

added is_splittable() (default 0)

cleaned up contig(), entire_seq() and attach_seq()

Ensembl/ensembl,willmclaren/ensembl,Ensembl/ensembl,Ensembl/ensembl,mjg17/ensembl,muffato/ensembl,danstaines/ensembl,at7/ensembl,james-monkeyshines/ensembl,at7/ensembl,muffato/ensembl,at7/ensembl,Ensembl/ensembl,mjg17/ensembl,at7/ensembl,mjg17/ensembl,james-monkeyshines/ensembl,muffato/ensembl,james-monkeyshines/ensembl,mjg17/ensembl,james-monkeyshines/ensembl,willmclaren/ensembl,danstaines/ensembl,danstaines/ensembl,muffato/ensembl