Multiple packages: use target-g++ instead of target-c++ as CXX

It is more explicit and conforms with other packages.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
libgdamm: add update macro

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
icu4c: symlink <lib>53.dll.a to <lib>.dll.a

Fixes #454.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
update package libusb1

The 1.0.19 release now uses VerSetConditionMask(), which is not
available by default in i686-pc-mingw32.static (but it *is* for
i686-w64-mingw32.static).

Thus, add 'CFLAGS=-D_WIN32_WINNT=0x0500' like in other packages
to make libusb1 also compile for i686-pc-mingw32.static.
Merge pull request #458 from uwehermann/libusb1_update

update package libusb1
flann: enable shared lib

With this commit the static libs are installed as "libflann.a" instead of
"libflann_s.a". pkg-config files are changed accordingly.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
flann: update

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
flann: enable OpenMP

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
boost: add $(BUILD_SHARED) guards to the `mv` of DLLs

Fixes #457.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
assimp: Fix update macro
flex: Fix update macro
libodbc++: Fix update macro
libusb1: Fix update macro
Merge pull request #459 from uwehermann/update_fixes

Update fixes