Numbering Post-Push is a good function for discussion in one post.
See the issue pcman-bbs#42(pcman-bbs#42).

1). Add a field PostPushNum in the line structure.
The line structure:
struct{ char[ColsPerPage], char='\0', CTermCharAttr[ColsPerPage, char=0]}
[ ColsPerPage*char + '\0' + ColsPerPage*CTermCharAttr + PostPushNum ]

2). Detect Post-Push lines and numbering them whenever a character is added in the screen buffer of CTermData.

3). Save the number in PostPushNum of Post-Push lines.

4). Draw PostPushNum in CTermView:DrawChar().

5). Fix a bug of buffer overflow in CTermData::InsertChar(). p.s. Though the function is not used now.