Give fluid and fltk-options their own .gitignore files

Move git exclusions from the main .gitignore file to the respective
directories to simplify the main file.

Note to devs: some file types are ignored "everywhere" (e.g. *.exe),
there's no need to add these files to the subdirs.

.gitignore

@@ -2,10 +2,15 @@
 # Files to be ignored by Git (do not commit)
 #
 
-*.o
-*.exe
+# Ignore everywhere, also in subdirectories
+
+*.bck
+*.exe
+*.o
+**/.DS_Store
+
+# CMake build artifacts if built in source - not recommended, but anyway
 
-# CMake
 bin/
 **/cmake_install.cmake
 **/CMakeCache.txt
@@ -19,13 +24,16 @@ FLTKConfig.cmake
 etc/FLTKConfig.cmake
 
 # MSVC
+
 *.tlog
 .vs/
 
 # VS Code (Visual Studio Code) Editor
+
 .vscode/
 
 # /
+
 /autom4te*.cache
 /build
 /clang
@@ -38,47 +46,33 @@ etc/FLTKConfig.cmake
 /fltk.list
 /fltk.spec
 /makeinclude
-/*.bck
 /TAGS
 
 # /FL
+
 /FL/fl_config.h
 /FL/Makefile
-/FL/*.bck
 
 # /cairo/
+
 /cairo/*.so*
 /cairo/*.dll
 
-# /documentation/
-# see documentation/.gitignore
-
-# /examples/
-# see examples/.gitignore
-
-# /fluid/
-/fluid/fluid
-/fluid/fluid-shared
-/fluid/*.bck
-/fluid/*.exe
-/fluid/TAGS
-/fluid/fluid.app
-/fluid/pixmaps/*.bck
-/fluid/documentation/html/
-
 # /lib/
+
 /lib/lib*
 /lib/*.lib
 /lib/*.a
 
 # /misc/
+
 /misc/doxystar
 
 # /src/
+
 /src/*.so*
 /src/*.sl*
 /src/*.a
-/src/*.bck
 /src/*.dll
 /src/*.sav
 /src/*.dylib
@@ -96,5 +90,3 @@ src/xdg-shell-protocol.c
 
 # libdecor/build/demo
 # libdecor/build/egl
-
-**/.DS_Store

fltk-options/.gitignore

@@ -0,0 +1,7 @@
+#
+# Files to be ignored by Git (do not commit)
+#
+
+fltk-options
+fltk-options-shared
+fltk-options.app

fluid/.gitignore

@@ -0,0 +1,13 @@
+#
+# Files to be ignored by Git (do not commit)
+#
+
+fluid
+fluid-shared
+TAGS
+fluid.app
+pixmaps/*.bck
+
+# local documentation generation
+
+documentation/html/