Please test pari-2.7.4 prerelease 1

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

Dear PARI developers,

I have made a prerelease of PARI 2.7.4

Please test the prerelease tarball:
<http://pari.math.u-bordeaux.fr/pub/pari/snapshots/pari-2.7.4-pre1.tar.gz>

This release include the mingw64 port contributed by Eric Driver.

The expected release date is set to the 19/06/2015.

Also please test the 64bit windows installer:
<http://pari.math.u-bordeaux.fr/pub/pari/windows/snapshots/Pari64-2-7-4-pre1.exe>

I have also built the 32bit windows installer:
<http://pari.math.u-bordeaux.fr/pub/pari/windows/snapshots/Pari32-2-7-4-pre1.exe>

Below is the changelog:

Done for version 2.7.4 (released 19/06/2015):
[last column crossreferences current development release 2.8.0]

  Fixed
    1- divisors([2,1]) -> SEGV                                   [#1664] [F84]
    2- acos([Pol(1)]) -> GC bug [#1663]                                  [F85]
    3- primes([1,Pol(2)]) -> SEGV [#1668]                                [F87]
    4- buffer overflow after default(format,"f.precision")               [F95]
    5- qfminim(A, 0, ...) -> stack overflow                      [#1682] [F97]
    6- div_scal_rfrac could create an invalid t_POL              [#1651] [F99]
    7- polroots(t_POL with leading coeff = 0) -> fp exception    [#1690] [F100]
    8- \r cannot deal with very long filenames                   [#1616] [F101]
    9- rnfisabelian(nf, non monic t_POL) -> SEGV                 [#1693] [F102]
   10- possibly incorrect result in nfdisc(T,listP)                      [F104]
   11- wrong dim(Ker) returned by ZM_pivot => SEGV in Z-linear algebra
       routines.  E.g. setrand(1);quadclassunit(-612556842419)   [#1700] [F105]
   12- moebius(factor(18)) -> 1 instead of 0                     [#1702] [F106]
   13- ispower(-167^10) => domain error                          [#1703] [F107]
   14- ispowerful(factor(0)) != ispowerful(0)                            [F108]
   15- expm1(2*I) => wrong result                                        [F109]
   16- gamma(1+a*x+O(x^2)) => error [#1707]                              [F110]
   17- printsep() printed its argument in random format instead of f_RAW [F111]
   18- nfdisc(x^10 - 29080*x^5 - 25772600) -> oo loop            [#1710] [F112]

  Added
ED  1- mingw64 support                                                   [A111]

Thanks in advance for testing,
Bill.