Added notice for 'alpha' features

platform.txt

@@ -31,7 +31,8 @@ compiler.warning_flags.default=
 compiler.warning_flags.more=-Wall -Wno-expansion-to-defined
 compiler.warning_flags.all=-Wall -Wextra -Wno-expansion-to-defined
 
-# maintain retrocompatibility
+# EXPERIMENTAL feature: optimization flags
+#  - this is alpha and may be subject to change without notice
 compiler.optimization_flags=-Os
 compiler.optimization_flags.release=-Os
 compiler.optimization_flags.debug=-Og -g3
@@ -228,8 +229,10 @@ tools.openocd-withbootsize.bootloader.pattern="{path}/{cmd}" {bootloader.verbose
 #
 # GDB (Debugger)
 #
+# EXPERIMENTAL feature: debug.pattern
+#  - this is alpha and may be subject to change without notice
 
 tools.gdb.path={runtime.tools.arm-none-eabi-gcc-7-2017q4.path}/bin/
 tools.gdb.cmd=arm-none-eabi-gdb
 tools.gdb.cmd.windows=arm-none-eabi-gdb.exe
-tools.gdb.debug.pattern="{path}/{cmd}" --interpreter=mi2 -ex "set pagination off" -ex 'target extended-remote | {tools.openocd.path}/{tools.openocd.cmd} -s "{tools.openocd.path}/share/openocd/scripts/" --file "{runtime.platform.path}/variants/{build.variant}/{build.openocdscript}" -c "gdb_port pipe" -c "telnet_port 0"' {build.path}/{build.project_name}.elf
+tools.gdb.debug.pattern="{path}/{cmd}" --interpreter=mi2 -ex "set pagination off" -ex 'target extended-remote | {tools.openocd.path}/{tools.openocd.cmd} -s "{tools.openocd.path}/share/openocd/scripts/" --file "{runtime.platform.path}/variants/{build.variant}/{build.openocdscript}" -c "gdb_port pipe" -c "telnet_port 0"' {build.path}/{build.project_name}.elf