fix broken msun link, add wikipedia link

...and various newline tweaks
to make the source more readable
(see http://rhodesmill.org/brandon/2012/one-sentence-per-line/)

README.md

@@ -1,34 +1,39 @@
 ## OpenLibm
 
 OpenLibm is an effort to have a high quality, portable, standalone
-`libm` library. It can be used standalone in applications and
-programming language implementations. 
+C mathematical library ([`libm`](http://en.wikipedia.org/wiki/libm)).
+It can be used standalone in applications
+and programming language implementations. 
 
-The project was born out of a need to have a good `libm` for the
-[Julia programming langage](http://www.julialang.org) that worked
-consistently across compilers and operating systems, and in 32-bit and
-64-bit environments.
+The project was born out of a need to have a good `libm`
+for the [Julia programming langage](http://www.julialang.org)
+that worked consistently across compilers and operating systems,
+and in 32-bit and 64-bit environments.
 
 ### History
 
-The OpenLibm code derives from the [FreeBSD
-msun](http://ftp.freebsd.org/pub/FreeBSD/FreeBSD/development/FreeBSD-CVS/src/lib/msun/)
-implementation, which in turn derives from [FDLIBM
-5.3](http://www.netlib.org/fdlibm/). As a result, it includes a number
-of fixes and updates to FDLIBM that have accumulated over the years in
-`msun`, and optimized versions of many functions.
+The OpenLibm code derives from the
+[FreeBSD msun](http://svnweb.freebsd.org/base/head/lib/msun/) implementation,
+which in turn derives from [FDLIBM 5.3](http://www.netlib.org/fdlibm/).
+As a result, it includes a number of fixes and updates to FDLIBM
+that have accumulated over the years in `msun`,
+and optimized versions of many functions.
 
 ### Platform support
 
-OpenLibm builds on Linux, Mac OS X, and Windows, and with little
-effort, should build on FreeBSD as well. It builds with both, GCC and
-clang. Although largely tested on x86, it also includes experimental
-support for ARM. The original `msun` also includes support for mips,
-sparc64, powerpc, ia64, and alpha. These are present in the OpenLibm
-source tree, but no attempt has been made to build any of these.
+OpenLibm builds on Linux, Mac OS X, and Windows,
+and with little effort, should build on FreeBSD as well.
+It builds with both GCC and clang.
+Although largely tested on x86,
+it also includes experimental support for ARM.
+The original `msun` also includes support for
+mips, sparc64, powerpc, ia64, and alpha.
+These are present in the OpenLibm source tree,
+but no attempt has been made to build any of these.
 
 ### Build instructions
 
-1. `make` or `make USEGCC=1` to build with GCC. This is the default on
-Linux and Windows.  
-2. `make USECLANG=1` to build with clang. This is the default on OS X.
+1. `make` or `make USEGCC=1` to build with GCC.
+   This is the default on Linux and Windows.  
+2. `make USECLANG=1` to build with clang.
+   This is the default on OS X.