cosmetics
add functions

get the class of a block (popcount)
get the maximum bits needed to store the offset of that class
add function

uses reverse table of mapping from block to offset within class
shortcut for 2^x
fix empty offset cell

write tests for that,
refactor some
add ccache to compilation in personal make-script
cosmetics
refactor: DRY popcount_tab, add tests
fix of by one bug in popcount_tab
coding convention cosmetics
add code generation scripts, cosmetics

class_gen.rb generates an abstract class, class_implement implements
that interface.

generated files should be compilable and splintable,
depending on lengts of names code lines might be longer than 80 chars
add completion config file to ignores
fix unused for assert=no
re-introduce GtCanvasClass into headers
add `gt dot' tool and associated stream
remove redundant definition
change lcp handling not to use gt_encseq_compare_viatwobitencoding()
Revert "iterate only once through sequences"

This reverts commit c77e8c3872d51f4c6fcceb55ac126e19cb580f3d.
Revert "switch to seqiterator"

This reverts commit 62214a3c647ec9c494327054c21f7311923d21e6.
improve performance

thanks Sascha!