lib/oelite: improve svn signature generation and handling
lib/oelite: improve svn signature generation and handling

* Handle symlinks properly and include file permission bits in svn source
  signatures.
* Get stored signature at parse time

(refs #251)

Signed-off-by: Esben Haabendal <c5ba3f1141bb30a64dd6c7e6726a53a85adc9442@prevas.dk>

sknsean/core,diorcety/oe-lite-core,hundeboll/core,diorcety/oe-lite-core,sknsean/core,hundeboll/core,sknsean/core,hundeboll/core,sknsean/core,hundeboll/core,sknsean/core