WARC-v0.0.0_7 - Web ARChive support for Perl

Changes for version 0.0.0_7 - 2019-10-22

implement reassembly of segmented WARC records
- WARC::Record::Logical
- WARC::Record::Logical::Block
- WARC::Record::Logical::Heuristics
records now carry the WARC::Collection that provided them
- allow storing additional parameters in record stubs
- WARC::Collection can now report if any index can search on a key
WARC::Record POD now includes a quick reference for which WARC headers are required for the various WARC record types
fix incomplete cloning of WARC::Fields objects
improve performance of "next" method on compressed records when the "sl" GZIP extended header is used

implement WARC::Collection
declare minimum version for dependency on Test::More
Index support improvements:
- indexes can now report ability to search on particular keys
- index entries can now be retrieved by position and can report their positions to provide for future metaindex support
- indexes can now search for WARC-Record-ID values
- CDX index files can now be read

quick release after previous release had a very high failure rate
fix bug in WARC::Record::FromVolume tests that caused failures on perl 5.18+ due to improved hash randomization
kill a bogus inherited constructor in WARC::Record::FromVolume
implement WARC::Index::Entry
add WARC::Record::Stub for load-on-demand record objects
replace platform-based test with direct feature test in WARC::Volume to determine if inode numbers from stat are valid
- The new test assumes that stat either returns a constant bogus inode number, or that the dev:ino fields are as POSIX requires.
declare dependencies on core modules to ensure that the installed version is included in test reports

quick release after previous release had 100% FAIL on CPAN Testers
fix bug in WARC::Record tests that was causing random failures
fix missing "use overload fallback => 1" in WARC::Volume
- bizarrely, the tests passed here without it
implement WARC::Index index system registration

skip POD verification test if Pod::Checker is too old
implement WARC::Date
implement WARC::Volume
implement basic support for reading WARC files
- WARC::Record::Block
- part of WARC::Record
- part of WARC::Record::FromVolume
WARC::Fields
- test performance improved
- ->as_block now uses strict UTF-8
- parsing tests now skipped if Perl core lacks in-memory files
document 'sl' gzip extension header generated by GNU Wget
- WARC::Builder will also support writing this header
- WARC::Record uses this header if available

skip POD verification test if Pod::Checker is not available
improve unit tests
- tests now "use strict" and "use warnings"
- tests now abort if loading target module fails
implement WARC::Fields
declare dependency on Scalar::Util for WARC::Fields