Released v5.0.0

• Change: CXC_INIT() detects PID change and automatically initializes necessary structures/vars.
• Change: Removed cxc_init_forked().
• Change: Removed __cxc_snprintf() from public header.
• Change: cxc_free_sec_buf(): arg changed to **pptr: buffer pointer is zeroed after the operation.
• Change: __cxc_sighdl_hook() renamed to CXC_REG_SIG_HOOK()
• Adedd: TEST: test_init_forked_throw(): test CXC_INIT() PID change detection in a forked process.
• Update: rcode v3.0: ABI changed!