empty "sharedStrings.xml" file

add empty sharedStrings.xml file

There should be no need, but it might help some readers.

remove dependencies

Merge pull request #4 from alicebob/reallynodep

really no deps

seems to work

Let's call this v1.

nil cells and better error checks

• allow 'nil' cells
• '.Close()` now returns if any error happened during any previous write as well.

fix for empty sheet

Empty sheets without any rows caused a panic.

fix timezones

v0.5.5

don't change the timezone of time.Time{}s

bool cells

v0.5.3

support booleans

pprof optimization

Unfortunately, writing xml by hand makes too much of a difference in speed.

license

v0.5.1

MIT license

seems to work

v0.5.0

add a write buffer