A few typo fixes to comments and the xz man page.

Thanks to Jim Meyering.

configure.ac

@@ -534,7 +534,7 @@ AC_TYPE_UINTPTR_T
 AC_CHECK_SIZEOF([size_t])
 
 # The command line tool can copy high resolution timestamps if such
-# information is availabe in struct stat. Otherwise one second accuracy
+# information is available in struct stat. Otherwise one second accuracy
 # is used.
 AC_CHECK_MEMBERS([
 	struct stat.st_atim.tv_nsec,

src/liblzma/check/sha256.c

@@ -6,7 +6,6 @@
 /// \todo       Crypto++ has x86 ASM optimizations. They use SSE so if they
 ///             are imported to liblzma, SSE instructions need to be used
 ///             conditionally to keep the code working on older boxes.
-///             We could also support using some external libary for SHA-256.
 //
 //  This code is based on the code found from 7-Zip, which has a modified
 //  version of the SHA-256 found from Crypto++ <http://www.cryptopp.com/>.

src/xz/xz.1

@@ -5,7 +5,7 @@
 .\" This file has been put into the public domain.
 .\" You can do whatever you want with this file.
 .\"
-.TH XZ 1 "2012-07-04" "Tukaani" "XZ Utils"
+.TH XZ 1 "2012-08-24" "Tukaani" "XZ Utils"
 .
 .SH NAME
 xz, unxz, xzcat, lzma, unlzma, lzcat \- Compress or decompress .xz and .lzma files
@@ -731,7 +731,7 @@ be dramatically higher than that of the single-threaded mode.
 DecMem contains the decompressor memory requirements.
 That is, the compression settings determine
 the memory requirements of the decompressor.
-The exact decompressor memory usage is slighly more than
+The exact decompressor memory usage is slightly more than
 the LZMA2 dictionary size, but the values in the table
 have been rounded up to the next full MiB.
 .RE