Recreated 3.1 branch from the trunk.

[From SVN r7839]

Removed 3.1 branch again since there were problems with the
svn:mergeinfo properties.

[From SVN r7838]

Removed now useless svn:mergeinfo properties.

[[Tag from zero-fileop commit at Subversion r7835]]

[From SVN r7835]

Removed annoying and useless svn:mergeinfo properties on some objects.

[[Tag from zero-fileop commit at Subversion r7834]]

[From SVN r7834]

Removed obsolete and never used 3.1 branch (will be replaced with the
current trunk).

[From SVN r7819]

Created 3.1 branch from the trunk r7782 (r7783 uses GMP internals
and makes the MPFR build fail on my machines, these changes mustn't
currently be incorporated in the 3.1 branch).

[From SVN r7785]

Removed the exp-int branch (no longer useful; the trunk can be built
with -D_MPFR_PREC_FORMAT=2).

[From SVN r7691]

MPFR 3.0.1 tag.

[From SVN r7615]

Deleted old svn:mergeinfo property on tests/random2.c

[[Tag from zero-fileop commit at Subversion r7079]]

[From SVN r7079]

Deleted old svn:mergeinfo property on tests/random2.c

[[Tag from zero-fileop commit at Subversion r7078]]

[From SVN r7078]

MPFR 3.0.0 tag.

[From SVN r6948]

Updated Subversion properties.

[[Tag from zero-fileop commit at Subversion r6848]]

[From SVN r6848]

Updated Subversion properties.

[[Tag from zero-fileop commit at Subversion r6845]]

[From SVN r6845]

Created branch 3.0.

[From SVN r6814]

MPFR 2.4.2 tag.

[From SVN r6606]

MPFR 2.4.1 tag.

[From SVN r6012]

MPFR 2.4.0 tag.

[From SVN r5892]

Removed 2.4.0 tag (a bug needs to be fixed before the release).

[From SVN r5815]

MPFR 2.4.0 tag.

[From SVN r5808]

Created new 2.4 branch from the trunk.

[From SVN r5704]