Fix the compile error on CentOS7 with gcc 4.8.2

1. Export the CPP_VERS to fix the compatibility issue of gcc;
2. Use -m64 and -m32 instead of the -m elf_x86_64 and -m elf_i386 separately
   when the gcc version is higher than 4.6.
   Because gcc does not support the linker-style since 4.6
3. Comment out the duplicated sense_buffer in struct pmcraid_cmd

[jerrylin.lxf@gmail.com: merge related commits]
Signed-off-by: Xiaofeng Lin <jerrylin.lxf@gmail.com>
Add mailing list in README.

Signed-off-by: Xiaofeng Lin <jerrylin.lxf@gmail.com>
1. Add the .gitignore file.
2. Add -Wall compile flag for libfsocket.so.
3. Use the '/* ... */' instead of multile "//" to comment out the multiple macro lines.
   The latter one will causes compile warning.
4. Use table instead of space in the libsocket.c to keep the unified coding style.
Add instruction to subscribe to the mailing list

Signed-off-by: Xiaofeng Lin <jerrylin.lxf@gmail.com>
Enhance the fastsocket_init for robustness
1. Check whether the socket_cachep is valid after create the kmem_cache_create.
2. Use goto statement to avoid some duplicated error handler codes.
Merge branch 'master' of github.com:fastos/fastsocket
Eliminate the compile warning of demo codes
1. Remove the unused varaibles.
2. Use the right format symbol "llu" instead of "lu" for 64 bits integer.
3. Add the -Werror compile flag.
Merge branch 'master' of github.com:fastos/fastsocket