package kit: some fixes for multi-version support

* Use enums/constants/functions instead of preprocessor macros.
* Missing include in PackageInfoAttributeValue.h.
* PackageReaderImpl::Init(): Check version before header size and
  return B_MISMATCHED_VALUES instead of B_BAD_DATA, if the version
  doesn't match. This allows callers to determine the condition and
  try a reader for a different version. A more flexible interface for
  that case would be nice, but since we want to support the old package
  version only temporarily, the current solution should be good enough.
Clone read support functionality for HPKG format version 1

It uses sub-namespace BPackage::BHPKG::V1. Unlike the one for the
current format version, the V1 version of BPackageInfoContentHandler
lives in BHPKG(::V1) sub-namespace and is private.
Bump HPKG format version
packagefs: PackageLeafNode: remove superfluous declaration
BPackageInfo: Support reading both HPKG format versions
BPackageDataReader: Remove unused Size(), BlockSize()
package kit: Add BAbstractBufferedDataReader

It doesn't do much in terms of buffering, but defines an interface
buffered readers can implement, namely the additional
ReadDataToOutput() which currently BPackageDataReader specifies.
package kit: internalize BPackageDataReader

It is no longer public (or even private) API. BPackageDataReaderFactory
returns a BAbstractBufferedDataReader instead. The advantage is that
the latter doesn't have hpkg format specific dependencies.
packagefs: Add support for hpkg format V1

* Add union-like class PackageData which wraps the V1 and V2
  BPackageData classes.
* GlobalFactory: Create a data reader depending on the data format
  version.
* Package: Add a loader for V1 format and try that, if the other one
  fails.
package list/extract: Add support for hpkg format V1
Remove resolvable provides type

* Remove BPackageResolvableType and respective property from
  BPackageResolvable.
* Remove package attribute B_HPKG_ATTRIBUTE_ID_PACKAGE_PROVIDES_TYPE.
Add "base package" package attribute
Rename BBlockBufferCache and friends to *Pool*

Also move BBlockBufferPoolNoLock into BHPKG namespace with the other
classes. Not sure why it wasn't there before.
Some comment updates
Some *DataReader improvements

* BFDDataReader: Add SetFD().
* BBufferDataReader: Derive from BAbstractBufferedDataReader.
hpkg format: compress the whole heap

Instead of handling compression for individual file/attribute data we
do now compress the whole heap where they are stored. This
significantly improves compression ratios. We still divide the
uncompressed data into 64 KiB chunks and use a chunk offset array for
the compressed chunks to allow for quick random access without too much
overhead. The tradeoff is a limited possible compression ratio -- i.e.
we won't be as good as tar.gz (though surprisingly with my test
archives we did better than zip).

The other package file sections (package attributes and TOC) are no
longer compressed individually. Their uncompressed data are simply
pushed onto the heap where the usual compression strategy applies. To
simplify things the repository format has been changed in the same
manner although it doesn't otherwise use the heap, since it only stores
meta data.

Due to the data compression having been exposed in public and private
API, this change touches a lot of package kit using code, including
packagefs and the boot loader packagefs support. The latter two haven't
been tested yet. Moreover packagefs needs a new kind of cache so we
avoid re-reading the same heap chunk for two different data items it
contains.
ZlibCompressor: Allow setting the compression level
Allow specifying the compression level for package creation

* Introduce BPackageWriterParameters which comprises all parameters
  for package creation, currently flags and compression level. Such an
  object can be passed to BPackageWriter::Init() and is passed on to
  PackageWriterImpl and WriterImplBase.
* PackageFileHeapWriter: Add compressionLevel property and pass the
  value on to ZlibCompressor.
* package add/create: Add options -0 ... -9 to specify the compression
  level to be used.
Add HAIKU_PACKAGE_COMPRESSION_LEVEL build variable

It allows to control the compression level used for package creation
and update. The default (9) is *very* slow, so developers may want to
use a smaller level during the regular development process to keep
turn-around times low.
PackageFileHeapWriter: Small style fix