[m-rev.] for review: improve the INSTALL scripts

[Julien Fischer]

Hi Zoltan,

On Fri, 21 Apr 2017, Zoltan Somogyi wrote:

> This should help avoid problems like the one today
> on m-users.
>
> For review by anyone.

> Improve the robustness of the INSTALL scripts.
> 
> .INSTALL.in:
> INSTALL.git:
>     Generate an error if the name of the current directory contains spaces.
> 
> .INSTALL.in:
>     Also generate an error if the current directory lacks a boehm_gc subdir,
>     indicating that it is not the resulting of unpacking a source distribution.

s/resulting/result/

That looks fine otherwise.

Julien