patch 7.4.2075

Problem:    No autocommand event to initialize a window or tab page.
Solution:   Add WinNew and TabNew events. (partly by Felipe Morales)

src/fileio.c

@@ -7706,6 +7706,7 @@ static struct event_name
     {"StdinReadPre",	EVENT_STDINREADPRE},
     {"SwapExists",	EVENT_SWAPEXISTS},
     {"Syntax",		EVENT_SYNTAX},
+    {"TabNew",		EVENT_TABNEW},
     {"TabEnter",	EVENT_TABENTER},
     {"TabLeave",	EVENT_TABLEAVE},
     {"TermChanged",	EVENT_TERMCHANGED},
@@ -7716,6 +7717,7 @@ static struct event_name
     {"VimEnter",	EVENT_VIMENTER},
     {"VimLeave",	EVENT_VIMLEAVE},
     {"VimLeavePre",	EVENT_VIMLEAVEPRE},
+    {"WinNew",		EVENT_WINNEW},
     {"WinEnter",	EVENT_WINENTER},
     {"WinLeave",	EVENT_WINLEAVE},
     {"VimResized",	EVENT_VIMRESIZED},