Error Handling

Currently, the lq-text library uses a fairly simplistic error handling policy that can result in calls to the system call exit. The function LQE_Error is called with an argument indicating the severity of the error, combined with bitwise `or' with any of a number of flags.
In addition, there are a number of wrappers for system calls that are integrated with the error handling mechanism. These routines perform in exactly the same way as the corresponding system calls or library functions if there are no errors, but, in the event of an error, call LQE_Error with a much clearer message than (for example) perror would generate.