Remove unneeded line from src/Makefile.am

Original nano commit: 4970
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4970
Original nano commit message:
	Removing an "-I m4" flag; it is needed only at the top level.
Make EXTRA_DIST only include things that are extra, not default

Original nano commit: 4971
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4971
Original nano commit message:
	Trimming the contents of EXTRA_DIST to what is beyond normal.
Update documentation with correct path to search history file

Original nano commit: 4972
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4972
Original nano commit message:
	Updating the docs for the changed location of nano's search history.
Remove 'gotolinecolumn' variable/logic from do_undo() and do_redo()

Original nano commit: 4975
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4975
Original nano commit:
	Removing an obsolete boolean variable.
Update 'placewewant' after undo/redo

Original nano commit: 4976
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4976
Original nano commit message:
	After an undo or redo, update the 'placewewant'.
	Patch by Mark Majeres.
Ensure cutbuffer is cleared appropriately

Original nano commit: 4978
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4978
Original nano commit message:
	Making sure the cutbuffer is cleared at the appropriate moments.
	Patch by Mark Majeres.
Eliminate unneeded 'to_end' member of 'undo' struct

Original nano commit: 4980
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4980
Original nano commit message:
	Eliding the in fact unneeded 'to_eof'
Remove unused 'strdata2' member of 'undo' struct

Original nano commit: 4981
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4981
Original nano commit message:
	And eliding a totally unused 'strdata2'.
UNSPLIT -> JOIN

Original nano commit: 4982
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4982
Original nano commit message:
	Renaming the undo type UNSPLIT to JOIN, for clarity.
Remove almost-assign-only 'type' member from 'rcoption' struct, and strtokeytype() function that was only used to set this
Remove condition/break that cancel out

Original nano commit: 4984
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4984
Original nano commit:
	Removing a condition and a break that cancel each other.
Rename no_more_space() to more_space() to better reflect its semantics

Original nano commit: 4985
http://svn.savannah.gnu.org/viewvc?view=rev&root=nano&revision=4985
Original nano commit message:
	Renaming 'no_more_space()' to 'more_space()' for consistency.
Update comments to reflect reality