build: make install in "/doc" failed if the destination dir contained spaces
This and the following commits try to add the necessary quoting in the build
scripts to make the process more robust.
The target for now is rendering "make deb" successful even when the base
directory contains spaces (eg. "/opt/mercu rial").
The build process should succeed without scattering files in spurious
directories (eg.: "/opt/mercu/usr/bin/hg").
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..