add SYMBOLPREFIX and SYMBOLSUFFIX makefile options

for adding a prefix or suffix to all exported symbol names in the shared library
Useful to avoid conflicts with other BLAS libraries, especially when using
64 bit integer interfaces in OpenBLAS

Note that since OSX does not have the objcopy utility, setting these options
to non-empty values on Mac requires the objconv tool, available (GPL license)
from http://www.agner.org/optimize/#objconv
Merge pull request #459 from tkelman/symbol-rename

add SYMBOLPREFIX and SYMBOLSUFFIX makefile options
#463 fixed a compiling bug on AIX.
refs #464. Fixed the bug of detecting L2 associative on x86.
 # The first commit's message is:
Optimizations for APM's xgene-1 (aarch64).

1) general system updates to support armv8 better.  Make all did not work, one needed to supply TARGET=ARMV8.
2) sgem 4x4 kernel in assembler using SIMD, and configuration changes to use it.
3) strmm 4x4 kernel in C.  Since the sgem kernel does 4x4, the trmm kernel must also do 4xN.

Added Dave Nuechterlein to the contributors list.
Fixed #456. Merged the optimizations for APM's
xgene-1 (aarch64).
Merge branch 'benedikt-huber-dave-patch' into develop
Refs #467. Added generic kernel file for x86_64.
Update organization info.
Refs #461. Provide OpenBLASConfig.cmake to support CMake.

If you "make PREFIX=/path/to/OpenBLAS install" ,
The config file will be located in /path/to/OpenBLAS/cmake

Then, you can use "find_package(OpenBLAS)" at CMake.
cmake -DOpenBLAS_DIR=/path/to/OpenBLAS/cmake ..
Update the doc for 0.2.13 version.
Merge branch 'develop'