Allow both forms of the Unicode representation of the TWO
CHARACTER COMBINING LIGATURE to be correctly translated to Marc8. 
Note if the resulting record is then translated back to Unicode using
marc4j the recommended single character ligature will be used even if
the original unicode record used the two half ligatures.
New code to support using numeric character references for all
characters outside the default base MARC8 character set, as a way to
work around programs that miss-handle the standard MARC8 escape
sequences.
Extensive changes, some to refactor the handling of Numeric Character
References (NCRs) in a more atomic way, so that if a NCR is supposed to
be decorated with a diacritic, the diacritic is handled properly.  Also
code to determine when an escape sequence to return to the default
character set has been deleted, and a slightly better attempt at
restoring damaged CJK character strings, when the original data is
damaged.
patch to java docs only.
Enable translating NCRs when converting from MARC8 to Unicode, and look
for instances of a CYRILLIC CAPITAL E having been replaced with a
subfield separator.
Add new test to convert Unicode record to MARC8 using Numeric Character
References instead of Escape sequences to other character sets, and then
convert the record back to Unicode and make sure it is identical.
Several new data files and tests associated with them to test
conversions to MARC8 using NCRs, and to test code that attempts to
heuristically fix mangled Greek, Russian, and CJK data.
Committing Release 2.6.3
changing implversion
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/org/marc4j/MarcPermissiveStreamReader.java
	test/src/org/marc4j/test/PermissiveReaderTest.java

Plus a new test (and new test data) to make sure the merged code is
working.