Merge pull request Ensembl#239 from ens-lgil/release/93

Fix an issue with the flag '--shift_hgvs'

Merging postreleasefix/90 to release/90

* postreleasefix/90:
  subversion update
  add some extra fork-failure safeguards, checks and tests

subversion update

Merging postreleasefix/90 to release/90

* postreleasefix/90:
  subversion update
  check SYMBOL exists before sedding it

Merging postreleasefix/90 to release/90

* postreleasefix/90:
  subversion update
  fix to cache_region_size and up_down_distance params causing overly long runtime

Merging postreleasefix/90 to release/90

* postreleasefix/90:
  subversion update
  fix isolated upstream bug
  format AF for insertion/deletion
  include insertions of size 1

subversion update

subversion update

subversion update

add bioperl-ext to docker image