remove ERS reader
.E1 and .E2 handled by ENVISAT reader
ENVISAT XCA files have no raster data but are still handled by this reader
separate actions for ASAR and ERS SAR
remove ERS reader from service
Merge branch 'ERSReader' of https://github.com/lveci/beam into lveci-ERSReader
typos
updated reader test fixtures according to ERS/Envisat change
Merge branch 'lveci-ERSReader'