Warnings during compilation

[rchar01]

There are several warnings when compiling version 20180408.203:

In ztree-diff-ediff-before-setup-hook-function:
ztree-diff.el:241:9:Warning: assignment to free variable
    ‘ztree-diff--ediff-previous-window-configuration’

In ztree-diff-ediff-quit-hook-function:
ztree-diff.el:250:29:Warning: reference to free variable
    ‘ztree-diff--ediff-previous-window-configuration’

In toplevel form:
ztree-view.el:189:1:Warning: Unused lexical variable ‘cur-pos’

In ztree-scroll-to-line:
ztree-view.el:205:17:Warning: reference to free variable ‘offset’

In end of data:
ztree-view.el:795:1:Warning: the following functions are not known to be
    defined: when-let, offset, incf

[fourier]

Supposedly fixed in last commit.

[rchar01]

Two compile warnings left:

In toplevel form:
ztree-view.el:190:1:Warning: Unused lexical variable ‘cur-pos’

In end of data:
ztree-view.el:796:1:Warning: the function ‘incf’ is not known to be defined.

[fourier]

Please check it out now.

[rchar01]

Now there are no warnings. Thanks.