clib2 Code

- Added dlclose(), dlerror(), dlopen() and dlsym() functions, which are
available only under OS4. There is a variant of dlopen() in libunix.a
which will perform a path name conversion.

- The shared object initialization has to be performed before any local
constructors are invoked, and after all local destructors have been
invoked.

- Preparations for clib2 1.205

- Added support for ELF shared objects and libraries. This is implemented through
constructor/destructor functions, which means that you can use this
functionality even in Amiga Exec style shared libraries, with the proper
library initialization code to invoke the constructor/destructor functions
for you.

- Updated uname() to recognize AmigaOS 4.1.

- The translation from Unix to Amiga path names did not properly process
multiple occurences of "/./" in the path name. Thanks go to Steven Solie
for finding the issue.

- The detection of "/./" and "/../" patterns in Unix path names to be
translated into Amiga path names did not test if it was overrunning
the end of the string.

- If strcmp(), strncmp() and memcmp() detect a pair of different
characters, then the function result must be calculated as if the
characters were of type "unsigned char". This is a requirement
according to the ISO 'C' (1994) standard. Thanks go to Georg Steger
for finding the issue.

- The definitions for INT_MIN, INT_MAX and UINT_MAX in <limits.h> no
longer use long integer types, as prompted by Steven Solie.

- Preparations for c.lib 1.204 release.

- Updated the build rules for use with GCC 4.2.x

- Added a workaround for the baserel build flavour, which requires a specific
GCC version, e.g. 4.0.4 or earlier.

- The memory allocated by malloc() and friends is now of type MEMF_PRIVATE
under OS4 and beyond. The AmigaOS 2.x/3.x compatible code will still
use MEMF_ANY in the same situation, though. Other uses of MEMF_ANY have
been replaced as well where MEMF_PRIVATE would have made better sense.

- I/O buffers allocated are now aligned according to the CPU cache line size,
if the operating system can supply that detailed information.

- Elaborated on the unidirectional/bidirectional PIPE: issues.

- stdlib_unsetenv.c needs stdio_headers.h to compile properly.

- It's iswpunct() and not iswpunc().