i.modis.import: change cwd to input data dir

[landam]

To reproduce

i.modis.import input=~/geodata/modis/MCD19A2.A2019031.h18v03.006.2019036210121.hdf -t --o
ls *.tif -w1
MCD19A2.A2019031.h18v03.single_AOD_QA.tif
MCD19A2.A2019031.h18v03.single_Optical_Depth_055.tif

Important on Windows

This is causing serious problem on Windows (here current working directory is set to C:\ by default).

[neteler]

Wouldn't it be better to use the standard .tmp directory of GRASS here, in the mapset?
We sometimes have the input directory as read only network directory, would that still work with this PR?

[landam]

Wouldn't it be better to use the standard .tmp directory of GRASS here, in the mapset?
We sometimes have the input directory as read only network directory, would that still work with this PR?

No, there must be write permission on the directory where temporary data is stored (see original problem on Windows).

Yes, I was thinking about .tmp, but there is -t flag.

  -t   Preserve temporary files (TIF and HDF mosaic)

In the case of -t flag it doesn't make sense to store temporary data in .tmp directory.

Option 1: store temporary data in input data dir (this PR)

Option 2: store temporary data in .tmp when -t is not given otherwise in input data dir

@neteler @lucadelu What do you think?

[neteler]

Will there be a fallback in case the input data directory is read only as it sometimes occurs?

[landam]

Will there be a fallback in case the input data directory is read only as it sometimes occurs?

Do you mean when -t flag given? @neteler What about this?

1. no -t flag -> use .tmp
2. -t flag -> use input data dir (if not writable fails with error)

OR

1. no -t flag -> use .tmp
2. use .tmp, after import copy temporary data to input data dir (if not writable fails with error, but data will imported anyway)

[lucadelu]

Will there be a fallback in case the input data directory is read only as it sometimes occurs?

Do you mean when -t flag given? @neteler What about this?

1. no -t flag -> use `.tmp`

2. -t flag -> use input data dir (if not writable fails with error)

I like more this option

[landam]

Wouldn't it be better to use the standard .tmp directory of GRASS here, in the mapset?
We sometimes have the input directory as read only network directory, would that still work with this PR?

It needs more effort especially for mosaics (create VRT file in different directory where HDF files are located).

[landam]

I took liberty to merge this PR in order to make this addon functional on Windows. @neteler Also related issues #203 open.