Update 1.8 branch for fix #1565
Update 1.8 branch for fix #1565
Revert "Update 1.8 branch for fix #1565"

This reverts commit da79093818cbbcdddbfe221127a7c2678cb1d3cc.
Revert "Update 1.8 branch for fix #1565"

This reverts commit f2a1e7a6f1c50d90dcacbae64ba8d6adb7997c1f.
Clean failure task and message utils
Add abstract pipeline module implementation

Move logger handling to a common abstract class.
Update index_fop.xsl
Support table/figure link styles for PDF #1267
Fix map serialization bug in job configuration

Since the job configuration format doesn't support file keys, the
internal storage must be a string.
Move job configuration reading to module invoker
Merge branch 'develop' of github.com:dita-ot/dita-ot into develop
Merge pull request #1587 from raducoravu/develop

Add basic PDF indexing using Apache FOP

Merged with modifications to minimize changed lines, and added link
separation with a comma and link styling
Use Ant project reference to store job configuration
Change coderef module to handle whether to process
Change conrefpush module to handle whether to process
Change keyref module to handle whether to process
Move file replacement to map meta reader

File modification and replacement were in two different classes, both
were moved to map meta reader. Also cleaned exception handling.
Fix unit tests for commit 2209ba3
Use URI and File instead of String in MoveMetaReader #1544
Add abstract filter that uses DOM