Remove check for stdscr from the configure

Thanks to jtbm37.
Merge branch 'remove-configure-check-for-stdscr'

Remove check for stdscr from the configure.

Thanks to jtbm37.

Closes #28.
Update NEWS file for v0.7.6
Version v0.7.6
Merge branch 'release-0.7.6'

vifm v0.7.6 release
-------------------

New minor version brings better integration with environment and external tools
as well as enhances file filtering capabilities in several ways.  Apart from
that, old features were tweaked and some build issues and bugs were resolved.
New Win32 and Win64 single-executable (no DLLs) packages appear first time with
this release.

This time beta stage was quite fruitful.  Thanks to all who installed and tried
beta versions, and special thanks to filterfalse.

Main changes:
 - added interactive local filter;
 - added external editing of command-line content with 'vicmd';
 - added integration with tmux;
 - added options to configure external commands for :apropos, :find, :grep
   and :locate commands;
 - added desktop entry file (\*nix only) and updated application icon;
 - fixed build for some combinations of OS/environments (OS X, 32/64-bit
   cygwin, Windows).

Notice: if you mapped q key to something, new q:, q/, q? and q= keys won't be
available; suggested solution is to change the mapping to qq.

More detailed list of changes.

Performance:
 - increased performance of (re)loading content for view mode (thanks to Robert
   Sarkozi).

Key bindings:
 - process [count] passed to gUU, gU<selector>, gUgU, gu<selector>, guu and gugu
   commands;
 - made all Ctrl-W x keys available in view mode (thanks to filterfalse);
 - changed meaning of the R key in view mode from redrawing view to reloading it
   preserving scroll position (thanks to Robert Sarkozi).

Normal and visual modes related changes:
 - added q:, q/, q? and q= keys (q= is defined for normal mode only) to prompt
   for command-line in external editor;
 - added "=" normal mode key, which activates file name filtering.

Command-line mode related changes:
 - added "=" and "filter" values for :history command, to show history of local
   filter;
 - added Ctrl-G key to start editing in external editor (for editing command,
   search pattern and file renames);
 - added optional argument for :invert command to control more kinds of
   inversion (thanks to filterfalse);
 - better order of command validity checks;
 - show better error message on unmatched quotes in command arguments;
 - store cancelled prompt input in prompt history;
 - check destination path existence before changing directory to it on :sync
   command;
 - use last search pattern as filename filter when :filter command gets an empty
   argument (:filter//, :filter"", :filter'') (thanks to filterfalse);
 - match only filename against pattern in :fileviewer instead of full path.

:set command and options:
 - added 'aproposprg', 'findprg', 'grepprg' and 'locateprg' options to specify
   external commands format;
 - added "fhistory" to 'vifminfo', which controls storing of local filter
   history;
 - added "f" flag to 'cpoptions' option.  It controls initial state of filename
   filter inversion for :filter[!] {regex} command (thanks to filterfalse);
 - from now on not absolute paths for the 'fusehome' options are rejected;
 - expand environment variables in values of the 'fusehome' and 'trashdir'
   options (thanks to filterfalse);
 - more adequate reaction on setting 'trashdir' option to wrong value;
 - do not reset selection on search when 'hlsearch' is reset (thanks to
   filterfalse).

File filtering:
 - distinguish files and directories in filename filter by appending a slash to
   names of directories;
 - separated file name filter into manual and automatic, mainly for convenience.

TUI (Text User Interface):
 - preserve current cursor position on view resorting;
 - force split-view when two paths are specified on command-line (thanks to
   filterfalse);
 - consider 'classify' option on displaying file name in the statusbar (thanks
   to Thomas Nemeth).

For Vim:
 - added syntax and filetype plugins for command-line editing buffers (thanks to
   filterfalse);
 - updated syntax file to highlight more elements (thanks to filterfalse).

Only on Windows:
 - filter files in case insensitive way on Windows;
 - don't wait finishing of GUI applications on Windows (thanks to Robert
   Sarkozi).

Other changes:
 - added integration with tmux (thanks to Seth VanHeulen, a.k.a. svanheulen);
 - added desktop entry file (thanks to Richard Benson);
 - added merge option for name conflict resolution, which allows for merging two
   directories overwriting files with matching names;
 - updated application icon (thanks to Richard Benson for making it);
 - don't overwrite directory stack stored in vifminfo on exit unless it was
   changed in current session;
 - improved documentation on several subjects;
 - display error after sourcing file with unmatched :if/:endif
   statements (thanks to filterfalse).

Major fixes:
 - fixed configuration when wcscasecmp(), wcsncasecmp() or set\_escdelay()
   functions is not available (thanks to Russell Urquhart);
 - fixed reserving of about 1 GiB piece of memory on 256-color terminals (sorry
   about that);
 - fixed running of executable with symbols that require escaping in their
   name (\*nix only).  Strangely enough, it wasn't noticed before;
 - fixed terminal hang after executing several external commands in a
   row (thanks to filterfalse);
 - fixed search of the first element in file list when displaying of parent
   directory is disabled;
 - fixed fails on running executables when 'fastrun' option is on (thanks to
   MadMaverick9).

See change log for full list of changes and by whom they were suggested.