#5968 Prevent race condition in `-dfont-ps-resdir`

[Masamichi Hosoda]

Prevent race condition in -dfont-ps-resdir

Issue 5968/4: Add Windows support for -dfont-ps-resdir

Windows environment could not use -dfont-ps-resdir option
because it used symlink.

This commit makes using file copying instead symlink when Windows.

Issue 5968/3: Prevent creating file race condition in -dfont-ps-resdir

For -dfont-ps-resdir,
we used creating file after checking the file existence.
However, when multiple lilypond processes were running,
as when using lilypond-book,
a race condition could cause creating file to fail.

This commit uses creating file method for -dfont-export-dir
that can prevent race condition.

Issue 5968/2: Prevent symlink race condition in -dfont-ps-resdir

For -dfont-ps-resdir,
we used symlink after checking the file existence.
However, when multiple lilypond processes were running,
as when using lilypond-book, a race condition could cause symlink to fail.

This commit makes preventing the race condition.

Issue 5968/1: Prevent mkdir race condition in -dfont-ps-resdir

For -dfont-ps-resdir,
we used mkdir after checking the directory existence.
However, when multiple lilypond processes were running,
as when using lilypond-book, a race condition could cause mkdir to fail.

This commit uses making directory method for -dfont-export-dir
that can prevent race condition.

http://codereview.appspot.com/561810045

[Anonymous]

Passes make, make check and a full make doc.

[Masamichi Hosoda]

Patch Set 2 : Improve messages
https://codereview.appspot.com/561810045/

[Anonymous]

Passes make, make check and a full make doc.