Cmake build: Use find_package_handle_standard_args() consistently
Cmake build: Search for spell checking libraries unconditionally

New option: LYX_REQUIRE_SPELLCHECK. If set and no spellchecker found
  stop the compilation
  if not set, compile in many speckeckers as possible from the set
  of 'ASPELL', 'Hunspell', 'Enchant'
Cmake build: Unify defines for spellchecker in config.h
* sk.po
Rename misleading parameter.

... and a typo and some whitespace.
Centralize replacement of "$$s"

Now the replacement is done in startScript(). In addition to making
the code cleaner and more consistent, this commit fixes a bug where
"$$s" was not replaced when "latex=" was specified in the extra flags
of a converter.

Note that the temporary fix at 731b8610 is reverted with this commit.
Centralize substitution of python commands

The code for detecting python commands and substituting in the
correct prefix is now merged with what used to be libScriptSearch()
and is now renamed to commandPrep(). This commit does not change
any functionality and just improves organization to reduce the
chance of bugs in the future.
Output a parbreak after a command.

This is what LyX was previously doing. It has no effect on vertical
spacing but, for example, sectioning commands stand out on the output.
The parbreak is not output if an environment follows or the alignment
of the current or next paragraph is changed.
Also remove some superfluous code.
Cmake build: Show the found flag for use of c++11 features
Make use of otexstream also in external::writeExternal

This was not necessary when LyX was generously outputting newlines.
As it may happen that the output produced by writeExternal (the
result of an external inset) starts right at the beginning of a
line, if otexstream does not know that something is already on
the line, the iomanip-like variable 'breakln' fails to actually
break the line.
Do not forget last word of paragraph in completion

With the old code, the last word of a paragraph would not be added in
the completion list. The key difference is to pass `from' instead of `pos'
to FontList::fontiterator.

Slight cleanup of the code.
Remove unused parameter.
Fix an on-screen representation glitch.

If a layout has NextNoIndent set to true, the following paragraph
is not indented on screen. LyX checks the previous layout for that
style parameter to decide whether to indent or not. Of course,
what matters is the latex output and the on-screen representation
should match this output. Now, when a layout has NextNoIndent==true,
the latex output is correctly not indented, while the on-screen
representation may fail to match this output. This can occur when,
for example, a standard paragraph is nested in the previous layout,
because LyX would check the property of the nested layout instead
of the container layout. Thus, LyX should check the property of a
previous layout at the same depth for correctly deciding whether
a paragraph has to be indented or not.
See also http://www.lyx.org/trac/ticket/9055#comment:12 for an
example document where the previous scenario actually occurs.
Adapt output to the on-screen representation.

LyX assumes that a standard paragraph following an aligned one or
a layout with NextNoIndent==false has to be indented on screen.
This means that in the latex output a blank line has to follow.
In this case there should be no problem as regards extra vertical
space and it simpler and more elegant to simply uncheck "Indent
Paragraph" in the Paragraph settings pane rather than changing
the current logic and allowing to insert a parbreak separator.
Fix alignment rendering of multirow in LyX (#8976)

Multirow cells now have the same alignment rendering in LyX
as in the output. The alignment of a multirow can change as
long as the column is not of fixed width. If the column is
of fixed width, the multirow is left-aligned.

When setting a multirow, the alignment is copied from
the last cell in the selection.
Graphics only handle inset-modify graphics (#8262)

inset-modify tabular and others are now passed on.
Add comment
#8849 catch exception in enchant speller backend and avoid multiple speller lookups for missing dictionaries
Correct my previous comment (thanks Kornel)
Add limits to searches in convert_TeX_brace_to_Argument.