Include new notify types

This HowTo explains, how new notify types can be added to code to make them configureable.

Message options allow you to configure, whether you want to receive notification messages for each type, whether a notification sound should be played (if associated) and whether game should stop on that event. These settings are stored in game data, so you could change settings as you wish depending on actual game advance.

Step by Step

1. add new enumeration values to nt_strings (src/client/menu/m_messages.c) and notify_t (src/client/menu/m_messages.h)
   • do not include any whitespaces in nt_strings - these codes are used to store settings and have to be read by MSG_ReadString as one string
   • feel free to rearrange defined types to group them (in the definitions) - as long as order is same for both definitions
   • see msgcategory definition to see how types can be grouped for options
   • don't forget to surround nt_strings value with N_() to get them found for translation
2. replace call of MN_AddNewMessage with MSO_CheckAddNewMessage with defined notify_t type
3. check whether to add default settings for new category to base/ufos/msgoptions.ufo
   • each line contains one "positive" setting - negative ones are not stored
4. check whether to add newly defined type to either existing msgcategory or define a new one (in base/ufos/msgcategories.ufo)