Don't use default parcel in tests
Switch to single parcel per file

.cfh files now must contain a single parcel definition at the start of
the file.
Don't allow default parcel in classes, vars, and types

The 'parcel' member of CFCVariables is always set to the parcel where
the variable is declared. This requires a change of the method
compatibility test. Only the method parameter types are compared for
equality while the symbols may differ.
Eliminate default parcel
Only add files from required parcels to hierarchy
Only write headers for required parcels
Add .cfp files to Perl install
Fix some comments regarding bool type
Fix for empty parcel list
Call yylex_destroy at the end of CFCParser_parse

This releases allocated memory and should reset globals like 'lineno'
in subsequent invocations.
Add line number to CFC parser error message

This sometimes reports the line following the actual syntax error but
it's a lot better than no line numbers at all.
Remove misleading comment from lemon Makefiles
Add --parcel option to cfc

The --parcel option can be used by non-Clownfish projects to add parcels
to the list of prerequisites. Example:

    cfc --include=PREFIX/share/clownfish/include --parcel=Lucy
Default Clownfish include dirs for Perl build

If no Clownfish include directories are passed to
Clownfish::CFC::Perl::Build, use the directories from the environment
variable CLOWNFISH_INCLUDE. If this variable is unset, use the system
include directories.

Also add all Clownfish include directories to the C include path.
MSVC flags shouldn't be needed for XS compilation
Define HAS_BOOL in source, not via compiler flags
Switch to Module::Build->depends_on

According to the Module::Build documentation, 'depends_on' is preferred
over 'dispatch' when calling actions from inside another action.

Calling 'dispatch' also has the side effect of localizing the
Module::Build properties hash. This makes it impossible to call an
action which changes some properties and use the changed properties
afterwards. The next commit relies on this feature.
Remove dependency of Clownfish::CFC::Perl::Build on Charmonizer

Add a new field 'cflags' to the 'clownfish_params' Module::Build
property to pass additional compiler flags.
Set -fvisibility flag via charmonizer
Bake parcel privacy defines into XS

The XS code can now be compiled without any extra compiler flags.