Released v1.5.0

• Change: CX_INIT(): cx_stack and sig stack are now placed in a single protected buffer with an additional locked page in between. The final buffer map looks like this: [xx][cx_stack][xx][sig_stack][xx] (xx - locked page). This way 1 page is saved per thread.
• Change: changed some variable types to get more optimal executable code, what have caused small changes to lib iface. Added few local vars to hold tls variables, what makes debug builds behaving more similarily to optimized ones.
• Change: cx_sig_handler() sets cx_entry.uval to siginfo->si_code, if user handler is not provided for current nesting level. si_code is representing a reason for sending the signal, so it represents "a class" of signal. Address is not as meaningfull from the runtime point of view.
• Fixed: cx_ldini(): should initialise the cx_stack ptr to NULL;
• Fixed: CX_DESTROY(): should set cx_ret on error.
• Fixed: CX_INIT(): cx_ninst must be set before calling CX_DESTROY()