[PD-dev] pd doesn't support staged installs (DESTDIR variable)

[mescalinum at gmail.com]

would be nice for this change to be included in all pd releases.
note that actually Pd must be patched [1] for making it install on 
Gentoo without the QA tool reporting access violations.

[1] one-liner fix:
sed -i -e 's:\($(libdir)/pd\):$(DESTDIR)\1:' makefile.in


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[from http://www.gnu.org/prep/standards]

|DESTDIR| is a variable prepended to each installed target file, like this:

     $(INSTALL_PROGRAM) foo $(DESTDIR)$(bindir)/foo
     $(INSTALL_DATA) libfoo.a $(DESTDIR)$(libdir)/libfoo.a

The |DESTDIR| variable is specified by the user on the |make| command 
line as an absolute file name. For example:

     make DESTDIR=/tmp/stage install

|DESTDIR| should be supported only in the |install*| and |uninstall*| 
targets, as those are the only targets where it is useful.

If your installation step would normally install /usr/local/bin/foo and 
/usr/local/lib/libfoo.a, then an installation invoked as in the example 
above would install /tmp/stage/usr/local/bin/foo and 
/tmp/stage/usr/local/lib/libfoo.a instead.

Prepending the variable |DESTDIR| to each target in this way provides 
for staged installs, where the installed files are not placed directly 
into their expected location but are instead copied into a temporary 
location (|DESTDIR|). However, installed files maintain their relative 
directory structure and any embedded file names will not be modified.

You should not set the value of |DESTDIR| in your Makefile at all; then 
the files are installed into their expected locations by default. Also, 
specifying |DESTDIR| should not change the operation of the software in 
any way, so its value should not be included in any file contents.

|DESTDIR| support is commonly used in package creation. It is also 
helpful to users who want to understand what a given package will 
install where, and to allow users who don't normally have permissions to 
install into protected areas to build and install before gaining those 
permissions. Finally, it can be useful with tools such as |stow|, where 
code is installed in one place but made to appear to be installed 
somewhere else using symbolic links or special mount operations. So, we 
strongly recommend GNU packages support |DESTDIR|, though it is not an 
absolute requirement.