1. New following OC function to read text file:

BOOL ocu_read_text_file(LPCSTR lpcszFilename, string* pstr);

Parameters:
    lpcszFilename = [input] full path file name
    pstr = [output] resulting file content as a string
Returns:
    FALSE if file not found

2. Improved OC function Column::SetFormat to support setting column custom format, for example:

void setcolumnformat_ex()
{
    Worksheet wks = Project.ActiveLayer();
    Column col1(wks, 0);
    col1.SetFormat(OKCOLTYPE_DATE, "yyyy'-'MM'-'dd");
    
    Column col2(wks, 1);
    col2.SetFormat(OKCOLTYPE_TEXT_NUMERIC, "DMS2");
    
    Column col3(wks, 2);
    col3.SetFormat(OKCOLTYPE_TIME, "hh mm ss'.'##");
}