Keep: [U済] strlen系と0の比較をやめる
Patches#651


git-svn-id: svn://svn.code.sf.net/p/sakura-editor/code/sakura/trunk@3137 f7ce1907-e4c7-47ca-9f76-12c87ed2c91c
Keep: [U済] CDropTargetクラス整理
Patches#667


git-svn-id: svn://svn.code.sf.net/p/sakura-editor/code/sakura/trunk@3138 f7ce1907-e4c7-47ca-9f76-12c87ed2c91c
Keep: [U済] os.h/os.cpp追加
Patches#668


git-svn-id: svn://svn.code.sf.net/p/sakura-editor/code/sakura/trunk@3141 f7ce1907-e4c7-47ca-9f76-12c87ed2c91c