(Breaking) Internals: ImStricmp/ImStrnicmp returned opposite sign when strings were different + ones in Demo.

Main functions unused by core imgui, so not strictly changing anything.
Demo functions were only comparing to 0.

imgui.cpp

diff --git a/imgui.cpp b/imgui.cpp
index a970e92..7ee8621 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -2265,14 +2265,14 @@
 int ImStricmp(const char* str1, const char* str2)
 {
     int d;
-    while ((d = ImToUpper(*str2) - ImToUpper(*str1)) == 0 && *str1) { str1++; str2++; }
+    while ((d = ImToUpper(*str1) - ImToUpper(*str2)) == 0 && *str1) { str1++; str2++; }
     return d;
 }
 
 int ImStrnicmp(const char* str1, const char* str2, size_t count)
 {
     int d = 0;
-    while (count > 0 && (d = ImToUpper(*str2) - ImToUpper(*str1)) == 0 && *str1) { str1++; str2++; count--; }
+    while (count > 0 && (d = ImToUpper(*str1) - ImToUpper(*str2)) == 0 && *str1) { str1++; str2++; count--; }
     return d;
 }
 

imgui_demo.cpp

diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 14da0ee..ede2eeb 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -9211,8 +9211,8 @@
     }
 
     // Portable helpers
-    static int   Stricmp(const char* s1, const char* s2)         { int d; while ((d = toupper(*s2) - toupper(*s1)) == 0 && *s1) { s1++; s2++; } return d; }
-    static int   Strnicmp(const char* s1, const char* s2, int n) { int d = 0; while (n > 0 && (d = toupper(*s2) - toupper(*s1)) == 0 && *s1) { s1++; s2++; n--; } return d; }
+    static int   Stricmp(const char* s1, const char* s2)         { int d; while ((d = toupper(*s1) - toupper(*s2)) == 0 && *s1) { s1++; s2++; } return d; }
+    static int   Strnicmp(const char* s1, const char* s2, int n) { int d = 0; while (n > 0 && (d = toupper(*s1) - toupper(*s2)) == 0 && *s1) { s1++; s2++; n--; } return d; }
     static char* Strdup(const char* s)                           { IM_ASSERT(s); size_t len = strlen(s) + 1; void* buf = ImGui::MemAlloc(len); IM_ASSERT(buf); return (char*)memcpy(buf, (const void*)s, len); }
     static void  Strtrimblanks(char* s)                          { char* str_end = s + strlen(s); while (str_end > s && str_end[-1] == ' ') str_end--; *str_end = 0; }