Update to 3.02

Upstream changes:
* v3.02 - 19th May 2018

No changes from v3.01_02

* v3.01_02 - 8th May 2018

BUG FIX: Uploads on MSWin32 were not correctly converted if the first
    character of a buffer was LF. Changed regex to negative lookarounds.

* v3.01_01 - 4th May 2018

BUG FIX: Uploads could fail if n * buffer_size fell inside the boundary
    marker. Thanks pru-mike (PR 1). (possibly fixes issue 116670)

BUG FIX: Changing the boundary marker for second and subsequent uploads
    causes errors. Thanks pru-mike (PR 1). (issue 125130)

Test suite enhanced: now with Test::Vars (0.12) and fix of tmp filename
    race condition.

(wen)