ConfigLocations_create():
  Creates a config file location handle
ConfigLocations_fgets():
  Read a line from the current config file that is open
ConfigLocations_open_file():
  Open a new current config file
ConfigLocations_open_folder():
  Open all config files (sorted alphanumerically) from a folder
ConfigLocations_open_glob():
  Open all config files matching a fnmatch/glob pattern
ConfigLocations_close()
  Close the current config file (and move to next)
ConfigLocations_free()
  Close all config files and free all resources

The fgets method also returns the line number/file path of the current file

As we process the lines returned by fgets we're able to ask the
handle to open a new pattern:

```C
    int debug_flag = 1
    const char * config_file_path = "my_config.conf";
    char buffer[1024];
    const char * current_file;
    int current_line_number;

    struct ConfigLocations *handle = ConfigLocations_create();
    ConfigLocations_open_file(handle, config_file_path, debug_flag);

    while (ConfigLocations_fgets(handle, &buffer, sizeof(buffer),
                                &current_file, &current_line_number,
                                debug_flag))
    {
        // Remove new line
        chat * end = strchr(buffer, '\n');
        if (end) *end = '\0';

        // Dump current file, line number, and line that was read:
        printf("%s[%d]: Read \"%s\"\n", current_file, line_number, buffer);

        // Look for lines starting "include "
        // We'll use this as an instruction to include additional files
        if (memcmp(buffer, "include ", sizeof("include ")-1) == 0) {
            // Remove the "include " from the start of the line
            char * pattern = buffer + sizeof("include ") - 1;
            // Treat the remainder as a glob:
            ConfigLocations_open_glob(handle, pattern, debug_flag);
            // Continue with the read loop that will now jump
            // to the included files
            continue;
        }
        // Do something with the config file lines we read
    }
    ConfigLocations_free(handle);
```

In this demo, we parse our config file (my_config.conf).
When we encounter a line "include glob_patter", we resolve all the
files that match this pattern and open them in order.

Each call to ConfigLocations_fgets reads from the current file
At EOF, it jumps to the next file matching the current glob
before finally returned back to the previous file

After a line like:
  include my_config.d/*.conf

each subsequent call to fgets will return a line from each *.conf file in that folder
before resuming reading from my_config.conf