concatenate and sort to remove duplicates

Following is the input. 1st and 3rd block are same(block starts here with '*' and ends before blank line) , 2nd and 4th blocks are also the same:

cat <file>
* Wed Feb 24  2016 Tariq Saeed <tariq.x.saeed@mail.com> 2.0.7-1.0.7
- add vmcore dump support for ocfs2 [bug: 22822573]

* Mon Jun 8 2015 Brian Maly <brian.maly@mail.com> 2.0.7-1.0.3
- Fix stall on failure in kdump init script [bug: 21111440]
- kexec-tools: fix fail to find mem hole failure on i386  [bug: 21111440]

* Wed Feb 24  2016 Tariq Saeed <tariq.x.saeed@mail.com> 2.0.7-1.0.7
- add vmcore dump support for ocfs2 [bug: 22822573]

* Mon Jun 8 2015 Brian Maly <brian.maly@mail.com> 2.0.7-1.0.3
- Fix stall on failure in kdump init script [bug: 21111440]
- kexec-tools: fix fail to find mem hole failure on i386  [bug: 21111440]

Expected Output:

* Wed Feb 24  2016 Tariq Saeed <tariq.x.saeed@mail.com> 2.0.7-1.0.7
- add vmcore dump support for ocfs2 [bug: 22822573]

* Mon Jun 8 2015 Brian Maly <brian.maly@mail.com> 2.0.7-1.0.3
- Fix stall on failure in kdump init script [bug: 21111440]
- kexec-tools: fix fail to find mem hole failure on i386  [bug: 21111440]

I have picked only four blocks of the file. There are myriad entries with duplicates.

I thought of combining lines and run uniq command but some blocks have two lines but some blocks have 3 lines.

cat | paste -d - - | uniq (This may not work for files more than 2 lines)

Could someone tell how to achieve the desired output?