keep int64 optimisation but removes INT64DEC id type
added alignment test
added value_description_test, fixed serialization and parsing of 128 bit integers
Revert "Fixed the == operator for INT64DEC and BIGDEC"

This reverts commit c7a9506ac84bb18aee3e6b5bb64b034fbaea0d34.
Merge branch 'int63dec-removal'

Conflicts:
	types/basic_value_descriptions.h
Merge branch 'value_description-testing'

Conflicts:
	types/basic_value_descriptions.h
	types/id.cc
restore INT64DEC for reconstitute only
throw when invoking toInt on a 128-bit integer
INT64DEC has been removed
128-bit ints are only parsed and serialized to/from string objects