Strict C89 compliance and fixing the rounding

This change includes the following:
- strict compliance with ANSI C89 standard. All POSIX functions are removed which enabled compiling this code on MS Visual Studio 11 running under Windows 7. However, MSVC generates tons of warnings related to "insecure" standard C functions (e.g., strtok, asctime, localtime, etc.). To fix this, we need to start having custom macro conditions in the code which I *DO NOT* want now. 
- Fixing the rounding of the generated prayer times to "DOWN". This is still an open issue and we need to see what Fiqh says regarding this.